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Sample records for include agar agarose

  1. Composition of agarose substrate affects behavioral output of Drosophila larvae

    Directory of Open Access Journals (Sweden)

    Anthi Aristomenis Apostolopoulou

    2014-01-01

    Full Text Available In the last decade the Drosophila larva has evolved into a simple model organism offering the opportunity to integrate molecular genetics with systems neuroscience. This led to a detailed understanding of the functional neuronal networks for a number of sensory functions and behaviors including olfaction, vision, gustation and learning and memory. Typically, behavioral assays in use exploit simple Petri dish setups with either agarose or agar as a substrate. However, neither the quality nor the concentration of the substrate is generally standardized across these experiments and there is no data available on how larval behavior is affected by such different substrates. Here, we have investigated the effects of different agarose concentrations on several larval behaviors. We demonstrate that agarose concentration is an important parameter, which affects all behaviors tested: preference, feeding, learning and locomotion. Larvae can discriminate between different agarose concentrations, they feed differently on them, they can learn to associate an agarose concentration with an odor stimulus and crawl faster on a substrate of higher agarose concentration. Additionally, we have investigated the effect of agarose concentration on three quinine based behaviors: preference, feeding and learning. We show that in all cases examined the behavioral output changes in an agarose concentration-dependent manner. Our results suggest that comparisons between experiments performed on substrates differing in agarose concentration should be done with caution. It should be taken into consideration that the agarose concentration can affect the behavioral output and thereby the experimental outcomes per se potentially due to an increased escape response on more rigid substrates.

  2. Molecular basis of an agarose metabolic pathway acquired by a human intestinal symbiont.

    Science.gov (United States)

    Pluvinage, Benjamin; Grondin, Julie M; Amundsen, Carolyn; Klassen, Leeann; Moote, Paul E; Xiao, Yao; Thomas, Dallas; Pudlo, Nicholas A; Anele, Anuoluwapo; Martens, Eric C; Inglis, G Douglas; Uwiera, Richard E R; Boraston, Alisdair B; Abbott, D Wade

    2018-03-13

    In red algae, the most abundant principal cell wall polysaccharides are mixed galactan agars, of which agarose is a common component. While bioconversion of agarose is predominantly catalyzed by bacteria that live in the oceans, agarases have been discovered in microorganisms that inhabit diverse terrestrial ecosystems, including human intestines. Here we comprehensively define the structure-function relationship of the agarolytic pathway from the human intestinal bacterium Bacteroides uniformis (Bu) NP1. Using recombinant agarases from Bu NP1 to completely depolymerize agarose, we demonstrate that a non-agarolytic Bu strain can grow on GAL released from agarose. This relationship underscores that rare nutrient utilization by intestinal bacteria is facilitated by the acquisition of highly specific enzymes that unlock inaccessible carbohydrate resources contained within unusual polysaccharides. Intriguingly, the agarolytic pathway is differentially distributed throughout geographically distinct human microbiomes, reflecting a complex historical context for agarose consumption by human beings.

  3. Agarose gels

    Science.gov (United States)

    2016-11-01

    Discovered in 17th-century Japan, agar is a jelly-like substance obtained by boiling algae, and it is widely used as a gelling agent for desserts in Japanese, Indian, Philippine and Vietnamese cuisine.

  4. Inoculation Expedition of Agar wood

    International Nuclear Information System (INIS)

    Peng, C.S.; Mohd Fajri Osman; Rusli Zakaria

    2015-01-01

    Inoculation expedition of agar wood is a main field works for researcher in Nuclear Malaysia to prove the real inoculation of agar wood in real jungle. These expeditions was conducted fourth times in the jungles of Malaysia including Gunung Tebu in Terengganu, Murum in Belaga, Sarawak, Kampung Timbang in Kota Belud, Sabah and Nuclear Malaysia itself. This expedition starts from preparation of samples and equipment, transportation into the jungle, searching and recognition of agar wood and lastly, inoculation of the agar wood. Safety aspects precedence set out in the preparation and implementation of this expedition. (author)

  5. Invitro Antidiabetic Activities of Agar, Agarosa, and Agaropectin from Gracilaria gigas Seaweed

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    Hardoko

    2015-11-01

    Full Text Available Some types of seaweed are reported to have antidiabet activity in vivo or in vitro, but the activity antidiabet fractions of polysaccharides from seaweed has not been widely reported. Gracilaria gigas is one type of red seaweed that can produce agar and it has two factions, namely agarose and agaropectin. The aim of this study was to obtain an agar extract, agarose fraction, agaropektin fraction of Gracilaria gigas and to determine the α-glucosidase inhibitory activity of extracts and the fractions. Extraction of agar that used an ethanol solution, and to fractionate agarose and agaropektin used dimetilsulfoxide solution. The results showed that the fraction of the agarose having lower sulfate content (0.28% compared with agar (5.91% and agaropektin (6.07%. Types of samples (agar, agarose, and agaropektin and sample doses significantly in inhibiting α-glucosidase enzyme activity. Agarose fraction has IC50 value against α-glucosidase lowest (96.86 ± 4.61 ppm, followed by the extract agar (116.63 ± 5.61 ppm, then the fraction agaropektin (158.34 ± 1.77 ppm.

  6. Current knowledge on agarolytic enzymes and the industrial potential of agar-derived sugars.

    Science.gov (United States)

    Yun, Eun Ju; Yu, Sora; Kim, Kyoung Heon

    2017-07-01

    Agar is a major cell wall carbohydrate of red macroalgae (Rhodophyta). Sugars derived from agar, such as agarooligosaccharides (AOSs), neoagarooligosaccharides (NAOSs), neoagarobiose (NAB), and 3,6-anhydro-L-galactose (L-AHG), possess various physiological activities. These agar-derived sugars can be produced by hydrolysis using chemicals or agarolytic enzymes. Despite the industrial potential of agar-derived sugars, their application has been hampered mainly due to the absence of efficient processes for the liquefaction and saccharification of agar. In this review, we have focused on strategies for producing high value-added sugars from agarose via chemical or enzymatic liquefaction and enzymatic saccharification. The liquefaction of agarose is a key step for preventing gelling and increasing the solubility of agarose in water by prehydrolyzing agarose into AOSs or NAOSs. For the industrial use of agar-derived sugars, AOS, NAOS, NAB, and L-AHG can be used as functional biomaterials owing to their physiological activities such as antiinflammation, skin whitening, and moisturizing. Recently, it was reported that AHG could be considered as a new anticariogenic sugar to replace xylitol. This review provides a comprehensive overview of processes for the hydrolysis of agar or agarose to produce high value-added sugars and the industrial application of these sugars.

  7. Purification and cloning of DNA fragments fractionated on agarose gels.

    Science.gov (United States)

    Griffin, H G; Gasson, M J

    1995-04-01

    Purification of DNA fragments from acrylamide or agarose gels is a commonly used technique in the molecular biology laboratory. This article describes a rapid, efficient, and inexpensive method of purifying DNA fractions from an agarose gel. The purified DNA is suitable for use in a wide range of applications including ligation using DNA ligase. The procedure uses standard high-melting-temperature agarose and normal TBE electrophoresis buffer. In addition, the protocol does not involve the use of highly toxic organic solvents such as phenol.

  8. Agarose isoelectrofocusing of intact virions.

    Science.gov (United States)

    Zerda, K S; Gerba, C P

    1984-08-01

    A convenient and accurate method for determining the isoelectric points of intact virions is described. Tritium-labeled poliovirus 1 (strains Brunhilde and LSc-2) and echovirus 1 (isolates V239, V248, V212, R115 and 4CH-1) were successfully focused into sharp bands at their respective isoelectric points using a thin-layer agarose isoelectric focusing system. In situ detection of labeled virus bands in the agarose was by fluorography. Freezing and thawing of virus samples prior to isoelectric focusing did not alter their respective isoelectric points.

  9. 21 CFR 184.1115 - Agar-agar.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Agar-agar. 184.1115 Section 184.1115 Food and Drugs... Substances Affirmed as GRAS § 184.1115 Agar-agar. (a) Agar-agar (CAS Reg. No. PM 9002-18-0) is a dried... ingredient is used in food in accordance with § 184.1(b)(2) under the following conditions: Maximum Usage...

  10. Separation of long RNA by agarose-formaldehyde gel electrophoresis.

    Science.gov (United States)

    Mansour, Farrah H; Pestov, Dimitri G

    2013-10-01

    We describe a method to facilitate electrophoretic separation of high-molecular-weight RNA species, such as ribosomal RNAs and their precursors, on agarose-formaldehyde gels. Two alternative "pK-matched" buffer systems were substituted for the traditionally used Mops-based conductive medium. The key advantages include shortened run times, a 5-fold reduction in formaldehyde concentration, a significantly improved resolution of long RNAs, and consistency in separation. The new procedure has a streamlined work flow that helps to minimize errors and is broadly applicable to agarose gel electrophoresis of RNA samples and their subsequent analysis by Northern blotting. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. A detailed study of homogeneous agarose/hydroxyapatite nanocomposites for load-bearing bone tissue.

    Science.gov (United States)

    Hu, Jingxiao; Zhu, Youjia; Tong, Hua; Shen, Xinyu; Chen, Li; Ran, Jiabing

    2016-01-01

    Agarose/hydroxyapatite (agar/HA) nanocomposites for load-bearing bone substitutes were successfully fabricated via a novel in situ precipitation method. Observation via SEM and TEM revealed that the spherical inorganic nanoparticles of approximately 50 nm were well dispersed in the organic matrix, and the crystallographic area combined closely with the amorphous area. The uniform dispersion of HA nanoparticles had prominent effect on improving the mechanical properties of the agar/HA nanocomposites (the highest elastic modulus: 1104.42 MPa; the highest compressive strength: 400.039 MPa), which proved to be potential load-bearing bone substitutes. The thermal stability of agarose and nanocomposites was also studied. The MG63 osteoblast-like cells on the composite disks displayed fusiform and polygonal morphology in the presence of HA, suggesting that the cell maturation was promoted. The results of cell proliferation and cell differentiation indicated that the cells cultured on the agar/HA composite disks significantly increased the alkaline phosphatase activity and calcium deposition. The structural role of agarose in the composite system was investigated to better understand the effect of biopolymer on structure and properties of the composites. The optimal properties were the result of a comprehensive synergy of the components. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. In vitro ovarian cancer model based on three-dimensional agarose hydrogel

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    Guojie Xu

    2014-01-01

    Full Text Available To establish a typical tumor model of ovarian cancer which may be more representative and reliable than traditional monolayer culture and pellet, agarose was used as cell vehicle to engineering tumor. Selection of agarose is based on its successful application in tissue engineering with both amenable mechanical and biological properties. In this study, ovarian cancer cell line SKOV3 was encapsulated in agarose hydrogel with cell aggregates and two-dimensional culture as controls. In vitro cell proliferation was assessed by MTT and cell viability was examined at time points of 2, 4, and 6 days. The expression of tumor malignancy markers including matrix metalloproteinase 2, matrix metalloproteinase 9, hypoxia-inducible factor-1α, and vascular endothelial growth factor–A was assessed by real-time polymerase chain reaction. The results showed that cells proliferated more rapidly in three-dimensional agarose culture than controls. Furthermore, upregulation of matrix metalloproteinase 9 and matrix metalloproteinase 2 activity and increased expression of vascular endothelial growth factor–A and hypoxia-inducible factor-1α were shown in agarose-engineered tumors. All the evidences demonstrated that agarose may provide a more favorable environment for cancer cell growth, mimicking the in vivo environment for tumor generation. The novel in vitro tumor model may be useful for the further investigation of anticancer therapeutics.

  13. Perencanaan Instalasi Pengolahan Air Limbah (IPAL Industri Agar-agar

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    Adelia Puspita Sari

    2017-01-01

    Full Text Available Industri agar-agar merupakan salah satu industri pangan yang menghasilkan limbah cair dalam jumlah besar terutama dari proses pencucian bahan baku. Bahan baku yang digunakan berasal dari rumput laut berjenis Gellidium sp., Gracillaria sp., dan Eucheuma Cottoni. Berdasarkan PerGub Jatim no. 72 tahun 2013 terdapat 6 parameter baku mutu air limbah yang harus dipenuhi sebelum membuang limbah ke badan air. Parameternya adalah BOD, COD, TSS, pH, ammonia dan sisa klor. Pada perencanaan ini digunakan data primer yang berasal dari industri agar-agar X yang berlokasi di Kab. Malang. Dari data yang didapat, dilakukan analisa kualitas sampel terhadap 6 parameter pencemar yang disesuaikan dengan baku mutu. Pengukuran salinitas juga dilakukan terhadap sampel. Sampel yang diambil dari 3 titik dengan menggunakan metode Integrated Sampling. Pada perencanaan ini digunakan data dari outlet 1 dan 2 yang tidak memenuhi ambang baku mutu dengan nilai BOD sebesar 514,4 mg/l, COD sebesar 1710,59 mg/l, dan TSS sebesar 269,26 mg/l. Sedangkan untuk parameter pencemar lainnya sudah memenuhi baku mutu. Unit IPAL yang direncanakan merupakan unit-unit pengolahan fisik-kimia. Unit IPAL terdiri dari bar screen, bak ekualisasi, prasedimentasi, koagulasi-flokulasi, sedimentasi dan filter dengan media zeolite. Pemilihan alternatif pengolahan didasarkan pada karakteristik limbah yang banyak mengandung bahan kimia terlarut untuk proses pencucian. Perhitungan BOQ dan RAB menggunakan HSPK Kota Malang 2015 dan didapatkan angka sebesar Rp141.665.444,00 untuk pembangunan seluruh unit IPAL.

  14. Synthesis of agarose-metal/semiconductor nanoparticles having ...

    Indian Academy of Sciences (India)

    Agarose, a naturally occurring biopolymer is used for the stabilization of metal, semiconductor nanoparticles. Ag and Cu nanoparticles stabilized in agarose matrix show excellent antibacterial activity against E. coli bacteria. The well dispersed metal nanoparticles within the agarose composite films can be readily converted ...

  15. Crosslinking of agarose bioplastic using citric acid.

    Science.gov (United States)

    Awadhiya, Ankur; Kumar, David; Verma, Vivek

    2016-10-20

    We report chemical crosslinking of agarose bioplastic using citric acid. Crosslinking was confirmed using Fourier transform infrared (FTIR) spectroscopy. The effects of crosslinking on the tensile strength, swelling, thermal stability, and degradability of the bioplastic were studied in detail. The tensile strength of the bioplastic films increased from 25.1MPa for control films up to a maximum of 52.7MPa for citric acid crosslinked films. At 37°C, the amount of water absorbed by crosslinked agarose bioplastic was only 11.5% of the amount absorbed by non-crosslinked controls. Thermogravimetric results showed that the crosslinked samples retain greater mass at high temperature (>450°C) than control samples. Moreover, while the crosslinked films were completely degradable, the rate of degradation was lower compared to non-crosslinked controls. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Rapid agarose gel electrophoretic mobility shift assay for quantitating protein: RNA interactions.

    Science.gov (United States)

    Ream, Jennifer A; Lewis, L Kevin; Lewis, Karen A

    2016-10-15

    Interactions between proteins and nucleic acids are frequently analyzed using electrophoretic mobility shift assays (EMSAs). This technique separates bound protein:nucleic acid complexes from free nucleic acids by electrophoresis, most commonly using polyacrylamide gels. The current study utilizes recent advances in agarose gel electrophoresis technology to develop a new EMSA protocol that is simpler and faster than traditional polyacrylamide methods. Agarose gels are normally run at low voltages (∼10 V/cm) to minimize heating and gel artifacts. In this study we demonstrate that EMSAs performed using agarose gels can be run at high voltages (≥20 V/cm) with 0.5 × TB (Tris-borate) buffer, allowing for short run times while simultaneously yielding high band resolution. Several parameters affecting band and image quality were optimized for the procedure, including gel thickness, agarose percentage, and applied voltage. Association of the siRNA-binding protein p19 with its target RNA was investigated using the new system. The agarose gel and conventional polyacrylamide gel methods generated similar apparent binding constants in side-by-side experiments. A particular advantage of the new approach described here is that the short run times (5-10 min) reduce opportunities for dissociation of bound complexes, an important concern in non-equilibrium nucleic acid binding experiments. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Analysis of Human Papillomavirus Genome Replication Using Two- and Three-Dimensional Agarose Gel Electrophoresis.

    Science.gov (United States)

    Henno, Liisi; Tombak, Eva-Maria; Geimanen, Jelizaveta; Orav, Marit; Ustav, Ene; Ustav, Mart

    2017-05-16

    This unit includes the necessary information to conduct neutral/neutral and neutral/alkaline two-dimensional and neutral/neutral/alkaline three-dimensional agarose gel electrophoresis. The methodology has been optimized over the years to gain a better outcome from the hard-to-interpret signals of human papilloma virus replication intermediates obtained from two- and three-dimensional agarose gels. Examples of typical results and interpretation of replication intermediate patterns are included, and the outcomes of multiple-dimension assays are assessed using previously published experimental data. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  18. Fenugreek hydrogel-agarose composite entrapped gold nanoparticles for acetylcholinesterase based biosensor for carbamates detection.

    Science.gov (United States)

    Kestwal, Rakesh Mohan; Bagal-Kestwal, Dipali; Chiang, Been-Huang

    2015-07-30

    A biosensor was fabricated to detect pesticides in food samples. Acetylcholinesterase was immobilized in a novel fenugreek hydrogel-agarose matrix with gold nanoparticles. Transparent thin films with superior mechanical strength and stability were obtained with 2% fenugreek hydrogel and 2% agarose. Immobilization of acetylcholinesterase on the membrane resulted in high enzyme retention efficiency (92%) and a significantly prolonged shelf life of the enzyme (half-life, 55 days). Transmission electron microscopy revealed that, gold nanoparticles (10-20 nm in diameter) were uniformly dispersed in the fenugreek hydrogel-agarose-acetylcholinesterase membrane. This immobilized enzyme-gold nanoparticle dip-strip system detected various carbamates, including carbofuran, oxamyl, methomyl, and carbaryl, with limits of detection of 2, 21, 113, and 236 nM (S/N = 3), respectively. Furthermore, the fabricated biosensor exhibited good testing capabilities when used to detect carbamates added to various fruit and vegetable samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Cell aggregation on agar as an indicator for cell-matrix adhesion: effects of opioids.

    Science.gov (United States)

    Debruyne, Delphine; Mareel, Marc; Vanhoecke, Barbara; Bracke, Marc

    2009-09-01

    The slow aggregation assay is generally used to study the functionality of cell-cell adhesion complexes. Single cells are seeded on a semisolid agar substrate in a 96-well plate and the cells spontaneously aggregate. We used HEK FLAG-MOP cells that stably overexpress the mu opioid receptor and the mu-opioid-receptor-selective agonists DAMGO and morphine to study whether other factors than functionality of cell-cell adhesions complexes can contribute to changes in the pattern of slow aggregation on agar. HEK FLAG-MOP cells formed small compact aggregates. In the presence of DAMGO and morphine, larger and fewer aggregates were formed in comparison to the vehicle control. These aggregates were localized in the center of the agar surface, whereas in the vehicle control they were dispersed over the substrate. However, in suspension culture on a Gyrotory shaker, no stimulation of aggregation was observed by DAMGO and morphine, showing that opioids do not affect affinity. A dissociation experiment revealed that HEK FLAG-MOP aggregates formed in the absence or presence of opioids are resistant to de-adhesion. We demonstrated that the larger aggregates are neither the result of cell growth stimulation by DAMGO and morphine. Since manipulations of the substrate such as increasing the agar concentration or mixing agar with agarose induced the same changes in the pattern of slow aggregation as treatment with opioids, we suggest that cell-substrate adhesion may be involved in opioid-stimulated aggregation.

  20. Nondenaturing agarose gel electrophoresis of RNA.

    Science.gov (United States)

    Rio, Donald C; Ares, Manuel; Hannon, Gregory J; Nilsen, Timothy W

    2010-06-01

    INTRODUCTION Perhaps the most important and certainly the most often used technique in RNA analysis is gel electrophoresis. Because RNAs are negatively charged, they migrate toward the anode in the presence of electric current. The gel acts as a sieve to selectively impede the migration of the RNA in proportion to its mass, given that its mass is generally proportional to its charge. Because mass is approximately related to chain length, the length of an RNA is more generally determined by its migration. In addition, topology (i.e., circularity) can affect migration, making RNAs appear longer on the gel than they actually are. There are two common types of gel: polyacrylamide and agarose. For most applications involving RNAs of or =600 nucleotides, and are especially useful for analysis of mRNAs (e.g., by Northern blotting). RNA analysis on agarose gels is essentially identical to DNA analysis (except that the gel boxes used must be dedicated to RNA work or to other ribonuclease-free work). Here we describe the use of straightforward Tris borate, EDTA (TBE) gels for routine analysis. These gels are appropriate for determining the quantity and integrity of RNA before using it for other applications. This procedure should not be used to determine size with accuracy, because the RNA will not remain in its extended state throughout the run.

  1. [Evaluation of blood agar medium for the growth of mycobacteria].

    Science.gov (United States)

    Coban, Ahmet Yılmaz; Akgüneş, Alper; Durupınar, Belma

    2011-10-01

    This study was aimed to evaluate the performance of blood agar for the growth of mycobacteria from clinical specimens sent to Mycobacteriology Laboratory of Samsun Chest Diseases Hospital. One hundred fifty six clinical specimens including 123 sputum, 28 bronchoalveolar lavage (BAL) and 5 pleural fluid specimens were inoculated in Löwenstein-Jensen (LJ), BACTEC MGIT 960 system (Becton Dickinson, USA) and blood agar following decontamination process. The specimens were also simultaneously examined for the presence of acid-fast bacilli (AFB). Thirty five mycobacteria strains (33 Mycobacterium tuberculosis and 2 atypical mycobacteria) grew in blood agar, 38 (36 M.tuberculosis and 2 atypical mycobacteria) in LJ media and 46 (44 M.tuberculosis and 2 atypical mycobacteria) in BACTEC MGIT 960 system. Among 29 AFB negative specimens, 20 revealed growth in both blood agar and LJ medium and 27 in MGIT system. AFB positive 20 samples yielded growth in 15 samples in blood agar, 18 in LJ medium and 19 in MGIT system. Among the total of 156 samples, contamination was observed in 15 (9.6%) samples in blood agar, 16 (10.2%) in LJ medium and 18 (11.5%) in MGIT system. Growth time was 5-35 days (mean 18 ± 7.4), 11-35 days (mean 19 ± 5.9) and 5-15 days (mean 10 ± 2.4) for blood agar, LJ medium and BACTEC MGIT 960 system, respectively. The three samples which revealed contamination in BACTEC MGIT 960 system, grew successfully in both blood agar and LJ medium without contamination. In one sample, growth was observed only in LJ medium but neither in blood agar nor BACTEC MGIT 960 system. However, in another sample, growth was observed only in blood agar while no growth was detected in LJ or BACTEC MGIT 960 system. Six samples yielded mycobacteria only in BACTEC MGIT 960 system. These results indicated that simultaneous use of one liquid and one solid medium to grow mycobacteria from the clinical samples seemed to be complementary. Blood agar was a promising choice since it was found

  2. Agarose gel electrophoretic detection of six beta-lactam antibiotic residues in milk.

    Science.gov (United States)

    Cutting, J H; Kiessling, W M; Bond, F L; McCarron, J E; Kreuzer, K S; Hurlbut, J A; Sofos, J N

    1995-01-01

    An electrophoretic method coupled with bioautography was developed for detection and identification of penicillin G, ampicillin, amoxicillin, cloxacillin, cephapirin, and ceftiofur residues in milk. The method uses a 2% agarose gel for electrophoresis, an overlay of PM indicator agar seeded with Bacillus stearothermophilus var. calidolactis, and incubation at 55 degrees C for 16-18 h. The new method separated and detected residues in milk at the levels of concern for the Food and Drug Administration (FDA) for penicillin G (5 ppb), cephapirin (20 ppb), and ceftiofur (50 ppb). The method also detected ampicillin, amoxicillin, and cloxacillin at 20, 30, and 30 ppb, respectively, but these levels are above those of concern for FDA (10 ppb).

  3. Agarose gel electrophoresis for the separation of DNA fragments.

    Science.gov (United States)

    Lee, Pei Yun; Costumbrado, John; Hsu, Chih-Yuan; Kim, Yong Hoon

    2012-04-20

    Agarose gel electrophoresis is the most effective way of separating DNA fragments of varying sizes ranging from 100 bp to 25 kb(1). Agarose is isolated from the seaweed genera Gelidium and Gracilaria, and consists of repeated agarobiose (L- and D-galactose) subunits(2). During gelation, agarose polymers associate non-covalently and form a network of bundles whose pore sizes determine a gel's molecular sieving properties. The use of agarose gel electrophoresis revolutionized the separation of DNA. Prior to the adoption of agarose gels, DNA was primarily separated using sucrose density gradient centrifugation, which only provided an approximation of size. To separate DNA using agarose gel electrophoresis, the DNA is loaded into pre-cast wells in the gel and a current applied. The phosphate backbone of the DNA (and RNA) molecule is negatively charged, therefore when placed in an electric field, DNA fragments will migrate to the positively charged anode. Because DNA has a uniform mass/charge ratio, DNA molecules are separated by size within an agarose gel in a pattern such that the distance traveled is inversely proportional to the log of its molecular weight(3). The leading model for DNA movement through an agarose gel is "biased reptation", whereby the leading edge moves forward and pulls the rest of the molecule along(4). The rate of migration of a DNA molecule through a gel is determined by the following: 1) size of DNA molecule; 2) agarose concentration; 3) DNA conformation(5); 4) voltage applied, 5) presence of ethidium bromide, 6) type of agarose and 7) electrophoresis buffer. After separation, the DNA molecules can be visualized under uv light after staining with an appropriate dye. By following this protocol, students should be able to: Understand the mechanism by which DNA fragments are separated within a gel matrix Understand how conformation of the DNA molecule will determine its mobility through a gel matrix Identify an agarose solution of appropriate

  4. Ethidium Bromide Modifies The Agarose Electrophoretic Mobility of CAG•CTG Alternative DNA Structures Generated by PCR

    Directory of Open Access Journals (Sweden)

    Mário Gomes-Pereira

    2017-05-01

    Full Text Available The abnormal expansion of unstable simple sequence DNA repeats can cause human disease through a variety of mechanisms, including gene loss-of-function, toxic gain-of-function of the encoded protein and toxicity of the repeat-containing RNA transcript. Disease-associated unstable DNA repeats display unusual biophysical properties, including the ability to adopt non-B-DNA structures. CAG•CTG trinucleotide sequences, in particular, have been most extensively studied and they can fold into slipped-stranded DNA structures, which have been proposed as mutation intermediates in repeat size expansion. Here, we describe a simple assay to detect unusual DNA structures generated by PCR amplification, based on their slow electrophoretic migration in agarose and on the effects of ethidium bromide on the mobility of structural isoforms through agarose gels. Notably, the inclusion of ethidium bromide in agarose gels and running buffer eliminates the detection of additional slow-migrating DNA species, which are detected in the absence of the intercalating dye and may be incorrectly classified as mutant alleles with larger than actual expansion sizes. Denaturing and re-annealing experiments confirmed the slipped-stranded nature of the additional DNA species observed in agarose gels. Thus, we have shown that genuine non-B-DNA conformations are generated during standard PCR amplification of CAG•CTG sequences and detected by agarose gel electrophoresis. In contrast, ethidium bromide does not change the multi-band electrophoretic profiles of repeat-containing PCR products through native polyacrylamide gels. These data have implications for the analysis of trinucleotide repeat DNA and possibly other types of unstable repetitive DNA sequences by standard agarose gel electrophoresis in diagnostic and research protocols. We suggest that proper sizing of CAG•CTG PCR products in agarose gels should be performed in the presence of ethidium bromide.

  5. Hichrom candida agar for identification of candida species

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    Baradkar V

    2010-01-01

    Full Text Available Chromogenic media are frequently used in direct and rapid identification of yeasts because different Candida species produce unique colors on these media. We used 60 isolates of Candida species including 30 C. albicans, 10 C. parapsilosis, 11 C. glabrata, five C. tropicalis, and four C. dubliniensis, isolated from various clinical specimens, to evaluate the performance of HiChrome Candida agar. These strains had been identified by germ tube test, morphology on cornmeal agar, chlamydospore formation on tobacco agar and sugar assimilation tests. The sensitivity and specificity results were: C. albicans (96.55 and 96.42%; C. parapsilosis (80 and 98.03%, C. glabrata (90.90 and 88.23%, C. tropicalis (100 and 100% and C. dubliniensis (60 and 96.55% respectively. HiChrom Candida agaris medium has been useful and capable of presumptive, rapid identification of Candida species within 48 hours.

  6. Investigation of the electrical properties of agarose gel: characterization of concentration using nyquist plot phase angle and the implications of a more comprehensive in vitro model of the brain

    OpenAIRE

    Pomfret, Roland; Sillay, Karl; Miranpuri, Gurwattan

    2013-01-01

    Background The electrical properties of agarose gel, namely impedance and capacitance, are relatively unexplored. Agarose gels are used as in vitro models in studies across numerous disciplines, including imaging, radiotherapy, infusion, and neurosurgery. Purpose In this study, we seek to characterize the impedance response of low concentration agarose gels by relating the gel concentrations to Nyquist Plot phase in order to establish a baseline with which to modify the response of the gel to...

  7. Uptake and Recovery of Lead by Agarose Gel Polymers

    OpenAIRE

    Anurag Pandey; Anupam Shukla; Lalitagauri Ray

    2009-01-01

    Problem statement: The uptake and recovery of lead ions were investigated by using agarose gel polymers. Approach: The experimental results showed that the agarose gel were effective in removing Pb (II) from solution. Biosorption equilibrium was approached within 4 h. Pseudo second-order was applicable to all the sorption data over the entire time range. Results: The sorption data conformed well to both the Langmuir and the Freundlich isotherm model. The ma...

  8. Agar agar-stabilized milled zerovalent iron particles for in situ groundwater remediation

    Energy Technology Data Exchange (ETDEWEB)

    Velimirovic, Milica; Schmid, Doris; Wagner, Stephan; Micić, Vesna; Kammer, Frank von der; Hofmann, Thilo, E-mail: thilo.hofmann@univie.ac.at

    2016-09-01

    Submicron-scale milled zerovalent iron (milled ZVI) particles produced by grinding macroscopic raw materials could provide a cost-effective alternative to nanoscale zerovalent iron (nZVI) particles for in situ degradation of chlorinated aliphatic hydrocarbons in groundwater. However, the aggregation and settling of bare milled ZVI particles from suspension presents a significant obstacle to their in situ application for groundwater remediation. In our investigations we reduced the rapid aggregation and settling rate of bare milled ZVI particles from suspension by stabilization with a “green” agar agar polymer. The transport potential of stabilized milled ZVI particle suspensions in a diverse array of natural heterogeneous porous media was evaluated in a series of well-controlled laboratory column experiments. The impact of agar agar on trichloroethene (TCE) removal by milled ZVI particles was assessed in laboratory-scale batch reactors. The use of agar agar significantly enhanced the transport of milled ZVI particles in all of the investigated porous media. Reactivity tests showed that the agar agar-stabilized milled ZVI particles were reactive towards TCE, but that their reactivity was an order of magnitude less than that of bare, non-stabilized milled ZVI particles. Our results suggest that milled ZVI particles could be used as an alternative to nZVI particles as their potential for emplacement into contaminated zone, their reactivity, and expected longevity are beneficial for in situ groundwater remediation. - Highlights: • Rapid aggregation and sedimentation were observed in bare milled ZVI particles. • Agar agar improved the stability of milled ZVI particle suspensions. • Agar agar enhanced the transport of milled ZVI particles in heterogeneous sands. • Agar agar reduced the reactivity of milled ZVI particles towards TCE.

  9. Agar agar-stabilized milled zerovalent iron particles for in situ groundwater remediation

    International Nuclear Information System (INIS)

    Velimirovic, Milica; Schmid, Doris; Wagner, Stephan; Micić, Vesna; Kammer, Frank von der; Hofmann, Thilo

    2016-01-01

    Submicron-scale milled zerovalent iron (milled ZVI) particles produced by grinding macroscopic raw materials could provide a cost-effective alternative to nanoscale zerovalent iron (nZVI) particles for in situ degradation of chlorinated aliphatic hydrocarbons in groundwater. However, the aggregation and settling of bare milled ZVI particles from suspension presents a significant obstacle to their in situ application for groundwater remediation. In our investigations we reduced the rapid aggregation and settling rate of bare milled ZVI particles from suspension by stabilization with a “green” agar agar polymer. The transport potential of stabilized milled ZVI particle suspensions in a diverse array of natural heterogeneous porous media was evaluated in a series of well-controlled laboratory column experiments. The impact of agar agar on trichloroethene (TCE) removal by milled ZVI particles was assessed in laboratory-scale batch reactors. The use of agar agar significantly enhanced the transport of milled ZVI particles in all of the investigated porous media. Reactivity tests showed that the agar agar-stabilized milled ZVI particles were reactive towards TCE, but that their reactivity was an order of magnitude less than that of bare, non-stabilized milled ZVI particles. Our results suggest that milled ZVI particles could be used as an alternative to nZVI particles as their potential for emplacement into contaminated zone, their reactivity, and expected longevity are beneficial for in situ groundwater remediation. - Highlights: • Rapid aggregation and sedimentation were observed in bare milled ZVI particles. • Agar agar improved the stability of milled ZVI particle suspensions. • Agar agar enhanced the transport of milled ZVI particles in heterogeneous sands. • Agar agar reduced the reactivity of milled ZVI particles towards TCE.

  10. Preparation of hydroxypropyl agars and their properties.

    Science.gov (United States)

    Zhang, Xiaodong; Liu, Xin; Cao, Mingzhao; Xia, Kai; Zhang, Yuqiao

    2015-09-20

    A series of hydroxypropyl agars (HPAs) with different hydroxypropyl molar substitution (MS) were prepared and their physicochemical properties were characterized. After hydroxypropylation, the dissolving temperature, the gelling temperature, the gel melting temperature, the gel strength, and the thermal stability of agar all decreased except that its hygroscopicity increased. The gel skeleton structures of raw agar and HPAs were all of the porous network structures, but the pores of gel skeleton structure of HPAs became smaller and denser. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Agar from some Hawaiian red algae

    Energy Technology Data Exchange (ETDEWEB)

    Santos, G.A.; Doty, M.S.

    1983-08-01

    From describing the agars of Gelidiella acerosa Forskk., Gelidium pluma Loomis, G. pusillum (Stackh.) Lejolis, Gracilaria abbotiana Hoyle, G. bursapastoris (Gmelin) Silva, G. canaliculata (Kutzing) Sonder, G. coronopifolia J.Ag., G. epihippisora Hoyle, Pterocladia caerulescens (Kutzing) Santelices and P. capillacea (Gmelin) Born. and Thur. as found in Hawaiian samples of these species, it is concluded that the species of Gelidium and especially Pterocladia and Gelidiella may merit more consideration for usage due to their agar gel strengths. The nature of the gel from Gracilaria abbottiana suggests the generic status might well be reexamined. The agars from the Gelidiella and the other Gracilaria species should be studied further for their prospective values to the food industry other than gel strength. Mixtures of the agars from G. bursapastoris and G. coronopifolia would merit attention for the taste texture of their mixtures. (Refs. 18).

  12. Aqueous phase catalytic conversion of agarose to 5-hydroxymethylfurfural by metal chlorides

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Lishi; Laskar, Dhrubojyoti D.; Lee, Suh-Jane; Yang, Bin

    2013-12-14

    Abstract: 5-HMF is a key intermediate for producing chemicals and fuels that can substitute for today’s petroleum-derived feedstocks. A series of metal chlorides, including NaCl, CaCl2, MgCl2, ZnCl2, CuCl2, FeCl3, and CrCl3, were comparatively investigated to catalyze agarose degradation for production of 5-HMF at temperature 180 oC, 200 oC, and 220 oC for 30 min, with catalyst concentration of 0.5% (w/w), 1% (w/w) and 5% (w/w), and substrate concentration of 2% (w/w). Our results revealed that alkali metal chlorides and alkali earth metal chlorides such as NaCl, CaCl2 and MgCl2 gave better 5-HMF yield compared with transition metal chlorides including ZnCl2, CrCl3, CuCl2 and FeCl3. 1% (w/w) MgCl2 was the more favorable catalyst for 5-HMF production from agarose, and resulted in 40.7% 5-HMF yield but no levulinic acid or lactic acid at 200 oC, 35 min. The reaction pathways of agarose degradation catalyzed by MgCl2 were also discussed.

  13. STABILITAS ANTOSIANIN JANTUNG PISANG KEPOK (Musa paradisiaca L TERHADAP CAHAYA SEBAGAI PEWARNA AGAR-AGAR

    Directory of Open Access Journals (Sweden)

    Lydia Ninan Lestario

    2015-02-01

    jantung pisang kepok yang disinari dengan intensitas 780-2.214 lux selama 10 jam masih disukai panelis, sedangkan yang disinari dengan intensitas 10.340 sudah tidak disukai panelis. Kata kunci: Antosianin, jantung pisang, agar-agar, intensitas cahaya, laju degradasi warna

  14. Comparison of blood agar, ampicillin blood agar, MacConkey-ampicillin-Tween agar, and modified cefsulodin-Irgasan-novobiocin agar for isolation of Aeromonas spp. from stool specimens.

    Science.gov (United States)

    Kelly, M T; Stroh, E M; Jessop, J

    1988-09-01

    The performance of four media for the isolation of Aeromonas strains from stool specimens, the importance of ampicillin-susceptible Aeromonas strains in the selection of culture media, and the usefulness of beta-hemolysis in screening blood-containing media for Aeromonas strains were evaluated in two phases. In the first phase, 36 of 1,672 stool specimens yielded Aeromonas isolates. Ninety-seven percent of the isolates were detected on blood agar containing 20 micrograms of ampicillin per ml (ABA), and 47% were detected on MacConkey agar containing 100 micrograms of ampicillin per ml and 1% Tween 80. In the second phase of the study, 43 of 1,924 stool specimens yielded Aeromonas isolates. Fifty-one percent of the isolates were detected on blood agar and on modified cefsulodin-Irgasan-novobiocin agar, and 84% were detected on ABA. The combination of ABA and modified cefsulodin-Irgasan-novobiocin agar provided 100% recovery of the Aeromonas isolates encountered. All of the Aeromonas isolates detected on blood agar were also detected on ABA, and 89% of the Aeromonas isolates detected on these media were beta-hemolytic. These results suggest that ABA is superior to the other media evaluated for the isolation of Aeromonas strains from stool specimens, but optimal recovery of the organism may require the use of more than one medium. The results also suggest that the occurrence of ampicillin-susceptible strains is not a limitation on the use of ABA, but at least 10% of Aeromonas isolates will be missed if beta-hemolysis is used to screen ABA plates for these organisms.

  15. Hydrogen peroxide agarose gels for electrophoretic analysis of RNA.

    Science.gov (United States)

    Pandey, Renu; Saluja, Daman

    2017-10-01

    Efficient electrophoretic separation of isolated total RNA utilizes chemicals and agents to aid in nuclease free environment. However cost, extensive pre-run processing protocols as well as toxic byproducts limit the usage of such protocols. Moreover, these treatments affect the overall electrophoretic results by altering the conductivity of the running buffer and weaken the gel strength. We here provide a protocol for RNA visualization that obviates these shortcomings by preparation of agarose gel with hydrogen peroxide using the regular TAE buffer. The simple, inexpensive protocol exhibits superior results in a horizontal agarose gel electrophoresis. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Extraction of agar from Gelidium sesquipedale (Rhodopyta) and surface characterization of agar based films.

    Science.gov (United States)

    Guerrero, P; Etxabide, A; Leceta, I; Peñalba, M; de la Caba, K

    2014-01-01

    The chemical structure of the agar obtained from Gelidium sesquipedale (Rhodophyta) has been determined by (13)C nuclear magnetic resonance ((13)C NMR) and Fourier transform infrared spectroscopy (FTIR). Agar (AG) films with different amounts of soy protein isolate (SPI) were prepared using a thermo-moulding method, and transparent and hydrophobic films were obtained and characterized. FTIR analysis provided a detailed description of the binding groups present in the films, such as carboxylic, hydroxyl and sulfonate groups, while the surface composition was examined using X-ray photoelectron spectroscopy (XPS). The changes observed by FTIR and XPS spectra suggested interactions between functional groups of agar and SPI. This is a novel approach to the characterization of agar-based films and provides knowledge about the compatibility of agar and soy protein for further investigation of the functional properties of biodegradable films based on these biopolymers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. High throughput generation and trapping of individual agarose microgel using microfluidic approach

    KAUST Repository

    Shi, Yang

    2013-02-28

    Microgel is a kind of biocompatible polymeric material, which has been widely used as micro-carriers in materials synthesis, drug delivery and cell biology applications. However, high-throughput generation of individual microgel for on-site analysis in a microdevice still remains a challenge. Here, we presented a simple and stable droplet microfluidic system to realize high-throughput generation and trapping of individual agarose microgels based on the synergetic effect of surface tension and hydrodynamic forces in microchannels and used it for 3-D cell culture in real-time. The established system was mainly composed of droplet generators with flow focusing T-junction and a series of array individual trap structures. The whole process including the independent agarose microgel formation, immobilization in trapping array and gelation in situ via temperature cooling could be realized on the integrated microdevice completely. The performance of this system was demonstrated by successfully encapsulating and culturing adenoid cystic carcinoma (ACCM) cells in the gelated agarose microgels. This established approach is simple, easy to operate, which can not only generate the micro-carriers with different components in parallel, but also monitor the cell behavior in 3D matrix in real-time. It can also be extended for applications in the area of material synthesis and tissue engineering. © 2013 Springer-Verlag Berlin Heidelberg.

  18. Characterization of a novel alkaline arylsulfatase from Marinomonas sp. FW-1 and its application in the desulfation of red seaweed agar.

    Science.gov (United States)

    Wang, Xueyan; Duan, Delin; Xu, Jiachao; Gao, Xin; Fu, Xiaoting

    2015-10-01

    A bacterial strain capable of hydrolyzing sulfate ester bonds of p-nitrophenyl sulfate (pNPS) and agar was isolated from the coast area of Qingdao, China. It was identified as Marinomonas based on its 16S rRNA gene sequence and named as Marinomonas sp. FW-1. An arylsulfatase with a recovery of 13 % and a fold of 12 was purified to a homogeneity using ion exchange and gel filtration chromatographies. The enzyme was composed of a single polypeptide chain with the molecular mass of 33 kDa estimated using SDS-PAGE. The optimal pH and temperature of arylsulfatase were pH 9.0 and 45, respectively. Arylsulfatase was stable over pH 8-11 and at temperature below 55 °C. The K m and V max of this enzyme for the hydrolysis of pNPS were determined to be 13.73 and 270.27 μM/min, respectively. The desulfation ratio against agar from red seaweed Gelidium amansii and Gracilaria lemaneiformis were 86.11 and 89.61 %, respectively. There was no difference between the DNA electrophoresis spectrum on the gel of the arylsulfatase-treated G. amansii agar and that of the commercial agarose. Therefore, this novel alkaline arylsulfatase might have a great potential for application in enzymatic conversion of agar to agarose.

  19. Micropipette Deflection Measurements of Agar-Glass Adhesion

    Science.gov (United States)

    Parg, Richard; Shelton, Erin; Dutcher, John

    Micropipette deflection experiments were used to study the adhesive strength at an agar-glass interface. Agar is a hydrogel commonly used in biological research; however, many of the mechanical properties of this hydrogel are not well characterized. By measuring the peak force required to slide an agar puck supported by a Teflon ring across a clean glass slide, we are able to compare the adhesive strength of 1 % w/w and 1.5 % w/w agar. On average, the force required to break the agar-glass interface was approximately a factor of 2 larger for 1.5 % w/w agar than for 1 % w/w agar. We discuss this result within the context of a simple model of agar adhesion. Additional experiments were performed to measure the kinetic friction between agar and glass to obtain insight into its dependence on agar concentration.

  20. 48 CFR 401.371 - AGAR Advisories.

    Science.gov (United States)

    2010-10-01

    ... communicate Department-wide policy and/or procedural guidance to contracting activities; (b) To delegate to... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false AGAR Advisories. 401.371 Section 401.371 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE GENERAL AGRICULTURE...

  1. Synthesis of agarose-metal/semiconductor nanoparticles having ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 120; Issue 6. Synthesis of agarose-metal/semiconductor nanoparticles having superior bacteriocidal activity and their simple conversion to metal-carbon composites. K K R Datta B Srinivasan H Balaram M Eswaramoorthy. Volume 120 Issue 6 November 2008 pp 579- ...

  2. Agarose Gel Size Selection for DNA Sequencing Libraries.

    Science.gov (United States)

    Mardis, Elaine; McCombie, W Richard

    2017-08-01

    Agarose gel electrophoresis may be used to purify fragmented genomic DNA after ligation of adaptors. After electrophoresis, the region of the gel containing the desired size range of DNA is excised, and the DNA is subsequently extracted from the gel and purified by passage through a spin column. © 2017 Cold Spring Harbor Laboratory Press.

  3. Diffusion properties of bacteriophages through agarose gel membrane.

    Science.gov (United States)

    Hu, Jun; Miyanaga, Kazuhiko; Tanji, Yasunori

    2010-01-01

    A simple two-chamber diffusion method was developed to study the diffusion properties of bacteriophages (phages). The apparent diffusion coefficients (D(app)) of Myoviridae phage T4 and filamentous phage fNEL were investigated, and the diffusion of the phages was found to be much slower than the diffusion of three antibiotics, ciprofloxacin, penicillin G, and tetracycline. D(app) of T4 and fNEL in water through filter paper were calculated to be 2.8 x 10⁻¹¹ m²/s and 6.8 x 10⁻¹² m²/s, respectively, and D(app) of fNEL through agarose gel membrane, an artificial biofilm, was also calculated to be smaller than that of T4. In addition, D(app) of phages through agarose gel was dependent on agarose concentration due to the similar size of phage and agarose gel mesh. We concluded that D(app) of phages through an artificial biofilm is dependent on both phage morphology and biofilm density, and suggest the use of this method to study diffusion properties through real biofilms. © 2010 American Institute of Chemical Engineers

  4. Recovery of DNA from agarose gel by trap method

    African Journals Online (AJOL)

    Administrator

    2011-09-05

    Sep 5, 2011 ... target band and refilling it with the same buffer. When the molecules of DNA move from agarose gel into a well, the velocity of DNA will increase in the well without interaction between gel and DNA (Stellwagen and. Stellwagen, 2009). It is possible to recover them from the. *Corresponding author. E-mail: ...

  5. High temperature and low acid pretreatment and agarase treatment of agarose for the production of sugar and ethanol from red seaweed biomass.

    Science.gov (United States)

    Kim, Hee Taek; Yun, Eun Ju; Wang, Damao; Chung, Jae Hyuk; Choi, In-Geol; Kim, Kyoung Heon

    2013-05-01

    To obtain fermentable sugar from agarose, pretreatment of agarose by using acetic acid was conducted for short durations (10-30 min) at low acid concentrations (1-5% (w/v)) and high temperatures (110-130 °C). On testing the pretreated agarose by using an endo-β-agarase I (DagA), an exo-β-agarase II (Aga50D), and neoagarobiose hydrolase (NABH), we observed that the addition of the endo-type agarase did not increase the sugar yield. Use of the crude enzyme of Vibrio sp. EJY3 in combination with Aga50D and NABH including acetic acid pretreatment resulted in a 1.3-fold increase in the final reducing sugar yield (62.8% of theoretical maximum based on galactose and 3,6-anhydrogalactose in the initial agarose), compared to those obtained using Aga50D and NABH only after acetic acid pretreatment. The simultaneous saccharification and fermentation of pretreated agarose yielded ethanol of 37.1% theoretical maximum yield from galactose contained in the pretreated agarose. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Investigation of the electrical properties of agarose gel: characterization of concentration using nyquist plot phase angle and the implications of a more comprehensive in vitro model of the brain.

    Science.gov (United States)

    Pomfret, Roland; Sillay, Karl; Miranpuri, Gurwattan

    2013-07-01

    The electrical properties of agarose gel, namely impedance and capacitance, are relatively unexplored. Agarose gels are used as in vitro models in studies across numerous disciplines, including imaging, radiotherapy, infusion, and neurosurgery. In this study, we seek to characterize the impedance response of low concentration agarose gels by relating the gel concentrations to Nyquist Plot phase in order to establish a baseline with which to modify the response of the gel to simulate that of in vivo brain tissue. This information is relevant to areas such as deep brain stimulation, and could have a significant impact on in vitro model design for such studies in the future. Ten agarose gels spanning four different concentrations were subjected to impedance spectroscopy using a Model 3387 DBS electrode. Phase angles were calculated and Cartesian Nyquist plots generated from the data. Results suggest that an inverse relationship exists between agarose gel concentration and phase angle. In addition, the results indicate that agarose gel reasonably emulates a constant phase element, which portrays the electrode-electrolyte interface impedance of some equivalent circuit models of brain tissue. The data shows that agarose gel is a suitable substrate for a deep brain stimulation in vitro model, but requires modification. In the future, we plan to utilize this data to determine the modifications necessary in the current agarose gel model to make it scientifically applicable to studies of both deep brain stimulation and infusion due to their overlapping variables.

  7. Melatonin Protects Human Cells from Clustered DNA Damages, Killing and Acquisition of Soft Agar Growth Induced by X-rays or 970 MeV/n Fe ions

    Energy Technology Data Exchange (ETDEWEB)

    Das, B.; Sutherland, B.; Bennett, P. V.; Cutter, N. C.; Sutherland, J. C.

    2011-06-01

    We tested the ability of melatonin (N-acetyl-5 methoxytryptamine), a highly effective radical scavenger and human hormone, to protect DNA in solution and in human cells against induction of complex DNA clusters and biological damage induced by low or high linear energy transfer radiation (100 kVp X-rays, 970 MeV/nucleon Fe ions). Plasmid DNA in solution was treated with increasing concentrations of melatonin (0.0-3.5 mM) and were irradiated with X-rays. Human cells (28SC monocytes) were also irradiated with X-rays and Fe ions with and without 2 mM melatonin. Agarose plugs containing genomic DNA were subjected to Contour Clamped Homogeneous Electrophoretic Field (CHEF) followed by imaging and clustered DNA damages were measured by using Number Average length analysis. Transformation experiments on human primary fibroblast cells using soft agar colony assay were carried out which were irradiated with Fe ions with or without 2 mM melatonin. In plasmid DNA in solution, melatonin reduced the induction of single- and double-strand breaks. Pretreatment of human 28SC cells for 24 h before irradiation with 2 mM melatonin reduced the level of X-ray induced double-strand breaks by {approx}50%, of abasic clustered damages about 40%, and of Fe ion-induced double-strand breaks (41% reduction) and abasic clusters (34% reduction). It decreased transformation to soft agar growth of human primary cells by a factor of 10, but reduced killing by Fe ions only by 20-40%. Melatonin's effective reduction of radiation-induced critical DNA damages, cell killing, and striking decrease of transformation suggest that it is an excellent candidate as a countermeasure against radiation exposure, including radiation exposure to astronaut crews in space travel.

  8. Agarose and methylcellulose hydrogel blends for nerve regeneration applications

    Science.gov (United States)

    Martin, Benton C.; Minner, Eric J.; Wiseman, Sherri L.; Klank, Rebecca L.; Gilbert, Ryan J.

    2008-06-01

    Trauma sustained to the central nervous system is a debilitating problem for thousands of people worldwide. Neuronal regeneration within the central nervous system is hindered by several factors, making a multi-faceted approach necessary. Two factors contributing to injury are the irregular geometry of injured sites and the absence of tissue to hold potential nerve guides and drug therapies. Biocompatible hydrogels, injectable at room temperature, that rapidly solidify at physiological temperatures (37 °C) are beneficial materials that could hold nerve guidance channels in place and be loaded with therapeutic agents to aid wound healing. Our studies have shown that thermoreversible methylcellulose can be combined with agarose to create hydrogel blends that accommodate these properties. Three separate novel hydrogel blends were created by mixing methylcellulose with one of the three different agaroses. Gelation time tests show that the blends solidify at a faster rate than base methylcellulose at 37 °C. Rheological data showed that the elastic modulus of the hydrogel blends rapidly increases at 37 °C. Culturing experiments reveal that the morphology of dissociated dorsal root ganglion neurons was not altered when the hydrogels were placed onto the cells. The different blends were further assessed using dissolution tests, pore size evaluations using scanning electron microscopy and measuring the force required for injection. This research demonstrates that blends of agarose and methylcellulose solidify much more quickly than plain methylcellulose, while solidifying at physiological temperatures where agarose cannot. These hydrogel blends, which solidify at physiological temperatures naturally, do not require ultraviolet light or synthetic chemical cross linkers to facilitate solidification. Thus, these hydrogel blends have potential use in delivering therapeutics and holding scaffolding in place within the nervous system.

  9. Nonwoven Carboxylated Agarose-Based Fiber Meshes with Antimicrobial Properties.

    Science.gov (United States)

    Forget, Aurelien; Arya, Neha; Randriantsilefisoa, Rotsiniaina; Miessmer, Florian; Buck, Marion; Ahmadi, Vincent; Jonas, Daniel; Blencowe, Anton; Shastri, V Prasad

    2016-12-12

    Hydrogel forming polysaccharides, such as the seaweed derived agarose, are well suited for wound dressing applications as they have excellent cell and soft tissue compatibility. For wound dressings, fibrous structure is desirable as the high surface area can favor adsorption of wound exudate and promote drug delivery. Although electrospinning offers a straightforward means to produce nonwoven fibrous polymeric structures, processing agarose and its derivatives into fibers through electrospinning is challenging as it has limited solubility in solvents other than water. In this study we describe the processing of carboxylated agarose (CA) fibers with antibacterial properties by electrospinning from a solution of the ionic liquid (IL) 1-butyl-3-methylimidazolium chloride ([Bmim] + Cl - ) possessing antimicrobial properties. The extent of carboxylation was found to impact fiber diameter, mesh elastic modulus, fiber swelling, and the loading and release of IL. IL-bearing CA fibers inhibited the growth of Staphylococcus aureus and Pseudomonas aeruginosa, bacteria commonly found in wound exudate. In sum, nonwoven CA fibers processed from IL are promising as biomaterials for wound dressing applications.

  10. Preparation and stability of agarose microcapsules containing BCG.

    Science.gov (United States)

    Esquisabel, A; Hernandez, R M; Igartua, M; Gascón, A R; Calvo, B; Pedraz, J L

    2002-01-01

    An emulsification/internal gelation method of preparing small-sized agarose microcapsules containing Bacillus Calmette-Guerin (BCG) is reported. Agarose microcapsules have been prepared by the emulsification of the hydrogel within a vegetable oil followed by its gelation due to the cooling of the system. Four different oils (sesame, sweet almonds, camomile and jojoba) were assayed. The rheological analysis of the oils showed a Newtonian behaviour, with viscosity values of 37.7, 51.2, 59.3 and 67.1 mPa s for jojoba, camomile, sesame and sweet almonds oil, respectively. The particle size of the microcapsules obtained ranged from 23.1 microm for the microcapsules prepared with sweet almonds oil to 42.6 microm for those prepared with jojoba. The microcapsule particle size was found to be dependent on the viscosity of the oil used in the emulsification step. The encapsulated BCG was identified by the Difco TB stain set K, followed by observation under optical microscopy. Once prepared, microcapsules were freeze-dried using 5% trehalose as cryoprotectant and the stability of the microcapsules was assayed during 12 months storage at room temperature, observing that agarose microcapsules were stable after 12 months storage, since there was no evidence of alteration in the freeze-dried appearance, resuspension rate, observation under microscope, or particle size.

  11. Preparative electrophoresis on linear polyacrylamide-agarose composite gels.

    Science.gov (United States)

    Shainoff, J R; Smejkal, G B; Mitkevich, O; DiBello, P M

    1996-01-01

    A preparative method for isolating centigram quantities of high molecular weight polypeptide chains with high resolution and recovery uses linear polyacrylamide/agarose composite (LPAC) gels as electrophoretic media from which the polypeptides can be easily extracted. The composites are prepared in a manner yielding linear copolymers of acrylamide and 1-allyloxy-2,3-propanediol within 2% agarose gels. After electrophoresis in sodium dodecyl sulfate (SDS), protein bands were rapidly visualized for excision by briefly immersing the gel in cold 0.1 M KCl which precipitates the protein-associated SDS. The gel slices are then freeze-thawed to disrupt the agarose matrix and promote syneresis of fluid upon centrifugation. The polypeptides are then separated from the polyacrylamide in the supernatant solution by precipitating with either acidic isopropanol, trichloroacetic acid, ammonium sulfate or other general protein precipitants. As determined with polypeptide chains of fibrinogen and its cross-linked derivatives, recoveries were virtually complete (95.4% +/- 2.2%), and were independent of molecular weights over the range tested (10(4) --10(6)).

  12. Standing Stock, Agar Yield and Properties of Gracilaria salicornia ...

    African Journals Online (AJOL)

    The highest mean biomass and cover values were obtained during the SE monsoon. Agar yield varied from 13.7 to 30.2 % (dry weight) and was highest during the dry NE monsoon period. Alkali treatment generally reduced agar yield by 25–56 %. Gel strength of the agar gels ranged between 118 and 251 g/cm2 and was ...

  13. Gari agar as culture media for mycological studies | Okorondu ...

    African Journals Online (AJOL)

    Gari agar was prepared by weighing 28 g of Gari, 14 g of agar powder and 8 g of Hibiscus rabdariffa powder to 1 L of sterile water. A conventional media, Sabouraud Dextrose Agar (SDA) was prepared as control according to manufacturer's procedure. Aliquot of appropriate dilutions of 1 g of agricultural soil was inoculated ...

  14. Agar alternatives for micropropagation of African violet ( Saintpaulia ...

    African Journals Online (AJOL)

    Agar is one of the most popular solidifying agents in plant tissue culture. High price of pure grade agar and fear of over exploitation of its resources caused searching for low cost alternatives. In this study, liquid medium with cotton substratum and different combinations of starch, semolina, potato powder and agar in two ...

  15. Comparative evaluation of chromogenic agar medium and conventional culture system for isolation and presumptive identification of uropathogens.

    Science.gov (United States)

    Akter, Laila; Haque, Rezwana; Salam, Md Abdus

    2014-09-01

    Urine is the most frequent specimen received for culture/sensitivity by clinical laboratories. The microbiological performance of HiCrome UTI agar medium was compared with Blood agar and MacConkey agar for isolation and presumptive identification of bacteria from urine culture. A total of 443 consecutively collected midstream and/or catheter-catch urine samples from patients attending the Islami Bank Medical College Hospital, Rajshahi, Bangladesh during January to December, 2012 were cultured. Urine samples showing pus cells ≥ 5/HPF were inoculated on to Blood agar (BA), MacConkey agar (MAC) and HiCrome UTI agar (CA) media simultaneously and incubated overnight aerobically at 37(0)C. Rate of isolation and presumptive identification of bacterial species were compared for different media. Culture yielded a total of 199 bacterial isolates from 189 (42.67%) positive plates including 179 (40.40%) unimicrobial and 10 (2.26%) polymicrobial (mixed growth of pair of bacteria) growths. Both HiCrome UTI agar and Blood agar media supported 100% growths while 151 (75.88%) growths were observed on MacConkey agar. The rate of presumptive identification was found significantly higher on HiCrome UTI agar (97.49%) than MAC agar (67.34%) (P<0.001) as primary urine culture medium. Of 199 isolates, E. coli was found to be the leading uropathogen isolated from 118 (59.30%) samples with its presumptive identification rate of 95.76%, 93.22% and 5.93% on CA, MAC and BA respectively. All 10 (100%) polymicrobial growths were demonstrated distinctly on CA against only 01(10%) on each BA and MAC. HiCrome UTI agar was found to be more useful as primary urine culture medium in both higher rate of isolation and presumptive identification of uropathogens in comparison to conventional media. Its inherent characteristics in demonstrating polymicrobial growth and ease of rapid identification by distinct colony colour are unique.

  16. Biological treatment of textile dyes by agar-agar immobilized consortium in a packed bed reactor.

    Science.gov (United States)

    Patel, Yogesh; Gupte, Akshaya

    2015-03-01

    The decolorization of Acid Maroon V was investigated using bacterial consortium EDPA containing Enterobacter dissolvens AGYP1 and Pseudomonas aeruginosa AGYP2 immobilized in different entrapment matrices. The consortium displayed 96% removal of dye (100 mg/l) within 6 h when immobilized in agar-agar. Under optimum concentrations of agar-agar (3.0% w/v) and cell biomass (0.9 g% w/v), the consortium displayed decolorization for 18 successive batches of Acid Maroon V and also decolorized 14 other different textile dyes. A packed bed reactor under batch mode showed 89% decolorization of dye after 56 repetitive cycles. Under continuous flow mode, maximum color removal was achieved with bed length of 36 cm, hydraulic retention time of 2.66 h, and dye concentration of 100 mg/l. Additionally, the reactor decolorized relatively higher concentrations (100-2000 mg/l) of dye. The synthetic dye wastewater containing five textile dyes was decolorized 92% with 62% COD reduction using an immobilized consortium.

  17. [Susceptibility testing of Mycobacterium tuberculosis isolates to primary antituberculous drugs on chocolate agar: a preliminary study].

    Science.gov (United States)

    Coban, Ahmet Yilmaz; Bilgin, Kemal; Akgüneş, Alper; Durupinar, Belma

    2008-07-01

    The aim of this study was to evaluate the use of chocolate agar as an alternative medium instead of Middlebrook 7H10 agar, for the susceptibility testing of Mycobacterium tuberculosis strains against isoniazid (INH), rifampicin (RIF), streptomycin (STR) and ethambutol (ETM). The susceptibility results obtained by chocolate agar were compared with the results of BACTEC 460 TB (Becton Dickinson, Sparks, MD, USA) system which was accepted as the reference method. A total of 25 M. tuberculosis clinical isolates were included to the study and susceptibility testing was performed on malachite green added-chocolate agar with some modifications of proportion method recommended by NCCLS. In our study when comparing the results obtained by chocolate agar with the results of BACTEC 460 TB system, the concordance rates for INH, STR, RIF and ETM were found as 88%, 88%, 84% and 72%, respectively. The specificity, sensitivity, positive and negative predictive values of susceptibility testing on chocolate agar have been detected as 82.3%, 100%, 72.7% and 100% for INH; 78.5%, 100%, 78.5% and 100% for RIF; 83.3%, 84.2%, 94.1% and 62.5% for STR; 25%, 94.1%, 72.7% and 66.6% for ETM, respectively. The results of the susceptibility testing performed on chocolate agar were obtained on the 21st day of incubation for all isolates. In conclusion, the data from our study suggested that chocolate agar can be used as an alternative medium for the susceptibility testing of M. tuberculosis, however, further studies with more isolates are needed for the standardisation of the method.

  18. Cleaning plaster surfaces with agar-agar gels: evaluation of the technique

    Directory of Open Access Journals (Sweden)

    Sonia Tortajada Hernando

    2013-07-01

    Full Text Available Abstract: Cleaning plaster surfaces represent a challenge for conservators It should only be performed following fully tested methods that guarantee the conservation of such fragile material. The goal of this work is to establishing a suitable cleaning method for this type of artworks from the tested concentrations and time of applications, using agar gels on plaster supports. Morphological, porosity and weight variations have been studied. Confocal and stereomicroscopy have been used as analytical techniques, as well as the measurement of water vapor permeability and weight have been taken on the samples. La limpieza de superficies de yeso-escayola con geles de agar-agar: evaluación de la técnica Resumen: La limpieza segura y eficiente de las superficies de yeso constituye un reto y una responsabilidad para el conservador-restaurador, y debe llevarse a cabo siguiendo métodos testados que garanticen su correcta conservación. La intención de este trabajo es determinar, a partir de las concentraciones y tiempos de aplicación ensayados, cuáles serían los parámetros óptimos para la ejecución de una limpieza eficaz e inocua empleando geles de agar-agar sobre soportes de yeso. Se han comprobado las posibles variaciones morfológicas de la superficie, las variaciones de la porosidad y del peso, así como la presencia de residuos, para lo cual se ha empleado la microscopía confocal, microscopía binocular, la medida de la permeabilidad al vapor de agua y la medida del peso de las muestras.

  19. Structural aspects of magnetic fluid stabilization in aqueous agarose solutions

    Science.gov (United States)

    Nagornyi, A. V.; Petrenko, V. I.; Avdeev, M. V.; Yelenich, O. V.; Solopan, S. O.; Belous, A. G.; Gruzinov, A. Yu.; Ivankov, O. I.; Bulavin, L. A.

    2017-06-01

    Structure characterization of magnetic fluids (MFs) synthesized by three different methods in aqueous solutions of agarose was done by means of small-angle neutron (SANS) and synchrotron X-ray scattering (SAXS). The differences in the complex aggregation observed in the studied magnetic fluids were related to different stabilizing procedures of the three kinds of MFs. The results of the analysis of the scattering (mean size of single polydisperse magnetic particles, fractal dimensions of the aggregates) are consistent with the data of transmission electron microscopy (TEM).

  20. On some agarics occurring in carr forests

    Directory of Open Access Journals (Sweden)

    Anna Bujakiewicz

    2013-12-01

    Full Text Available Remarks on ecology of several small agarics growing in carr forests of Querco-Ulmetum minoris and Astrantio-Fraxinetum type are presented and discussed. They all occupy special microhabitat (bare ground, belong to certain functional group (saprotrophs and seem to be connected with carr forest habitat. The base rich or neutral soil humus, generally not favoured by fungi, together with extreme moisture and fast decomposition of litter causes that some humicolous macrofungi in carr forests form mostly small and short-living fruit bodies of hygrophyte character. They represent several genera: Conocybe, Coprinus, Cystolepiota, Entoloma, Flammulaster, Lepiota, Melanophyllum and Pholiotina of the order Agaricales. New localities are given, ecological amplitude is analised and preliminary mycosynusial consideration is presented.

  1. Chocolate agar, a differential medium for gram-positive cocci.

    OpenAIRE

    Gunn, B A

    1984-01-01

    Reactions incurred on chocolate agar by gram-positive cocci were correlated with species identity. Darkening and clearing of the medium was usually associated with the species Staphylococcus epidermidis, Staphylococcus aureus, Staphylococcus simulans, and Streptococcus faecalis. Yellowing of chocolate agar was associated with alpha-hemolytic species of Streptococcus. The study demonstrated that reactions occurring on chocolate agar are useful in identifying gram-positive cocci.

  2. Evaluation of CP Chromo Select Agar for the enumeration of Clostridium perfringens from water.

    Science.gov (United States)

    Manafi, Mammad; Waldherr, Kerstin; Kundi, Michael

    2013-10-01

    The European Directive on drinking water quality has included mCP agar as the reference method for recovering Clostridium perfringens from drinking waters. In the present study, three media (mCP, TSCF and CP Chromo Select Agar) were evaluated for recovery of C. perfringens in different surface water samples. Out of 139 water samples, using a membrane filtration technique, 131 samples (94.2%) were found to be presumptively positive for C. perfringens in at least one of the culture media. Green colored colonies on CP Chromo Select Agar (CCP agar) were counted as presumptive C. perfringens isolates. Out of 483 green colonies on CCP agar, 96.3% (465 strains, indole negative) were identified as C. perfringens, and 15 strains (3.1%) were indole positive and were identified as Clostridium sordellii, Clostridium bifermentans or Clostridium tetani. Only 3 strains (0.6%) gave false positive results and were identified as Clostridium fallax, Clostridium botulinum, and Clostridium tertium. Variance analysis of the data obtained shows statistically no significant differences in the counts obtained between media employed in this work. The mCP method is very onerous for routine screening and bacterial colonies could not be used for further biochemical testing. The colonies on CCP and TSCF were easy to count and subculture for confirmation tests. TSCF detects sulfite-reducing clostridia, including species other than C. perfringens, and in some cases excessive blackening of the agar frustrated counting of the colonies. If the contamination was too high, TSCF did not consistently produce black colonies and as a consequence, the colonies were white and gave false negative results. On the other hand, the identification of typical and atypical colonies isolated from all media demonstrated that CCP agar was the most useful medium for C. perfringens recovery in water samples. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Estudio comparativo del agar Iso-Sensitest y el agar Mueller-Hinton

    Directory of Open Access Journals (Sweden)

    Margaret Ordoñez Smith de Danies

    1993-12-01

    Full Text Available Se estudiaron 710 cepas bacterianas provenientes de diferentes muestras para comparar las zonas de inhibición de los diámetros obtenidos en agar Iso-Sensitest y el agar Mueller Hinton. Se realizaron bajo la técnica de difusión en disco de la NCCLS (Comité Nacional para los Estándares de Laboratorio Clínico. Estadísticamente, al analizar el chi-cuadrado de las muestras estudiadas, se observó una confiabilidad del 99%, por lo tanto no hay diferencia entre los dos medios de cultivo. En el agar Iso-Sensitest se obtuvo una mejor nitidez con los diámetros de los halos de inhibición, se encontró un 62,0% de mejor lectura o mayor visibilidad en los diámetros de las zonas de inhibición con los cultivos de Enterococcus sp., un 21,4% con el Staphylococcus aureus y 20,0% en el caso de la Providencia stuartii.

  4. Primary Klebsiella identification with MacConkey-inositol-carbenicillin agar.

    Science.gov (United States)

    Bagley, S T; Seidler, R J

    1978-09-01

    MacConkey-inositol-carbenicillin agar has successfully been used as a primary selective medium for Klebsiella enumeration. With pure cultures, nearly 100% recovery of Klebsiella was observed by membrane filtration. With environmental samples using membrane filtration, 95% of typical pink- to red-colored colonies were verified as Klebsiella, as opposed to only 1% of yellow background colonies. Recovery of Klebsiella on MacConkey-inositol-carbenicillin agar was as good or better than on mEndo agar LES (Difco Laboratories). Recovery and percent colony confirmation with MacConkey-inositol-carbenicillin agar were greater than for other proposed Klebsiella selective media.

  5. Hollow agarose microneedle with silver coating for intradermal surface-enhanced Raman measurements: a skin-mimicking phantom study

    Science.gov (United States)

    Yuen, Clement; Liu, Quan

    2015-06-01

    Human intradermal components contain important clinical information beneficial to the field of immunology and disease diagnosis. Although microneedles have shown great potential to act as probes to break the human skin barrier for the minimally invasive measurement of intradermal components, metal microneedles that include stainless steel could cause the following problems: (1) sharp waste production, and (2) contamination due to reuse of microneedles especially in developing regions. In this study, we fabricate agarose microneedles coated with a layer of silver (Ag) and demonstrate their use as a probe for the realization of intradermal surface-enhanced Raman scattering measurements in a set of skin-mimicking phantoms. The Ag-coated agarose microneedle quantifies a range of glucose concentrations from 5 to 150 mM inside the skin phantoms with a root-mean-square error of 5.1 mM within 10 s. The needle is found enlarged by 53.9% after another 6 min inside the phantom. The shape-changing capability of this agarose microneedle ensures that the reuse of these microneedles is impossible, thus avoiding sharp waste production and preventing needle contamination, which shows the great potential for safe and effective needle-based measurements.

  6. Mass production of spores of lactic acid-producing Rhizopus oryzae NBRC 5384 on agar plate.

    Science.gov (United States)

    Yamane, Tsuneo; Tanaka, Ryosuke

    2013-01-01

    Mass production of sporangiospores (spores) of Rhizopus oryzae NBRC 5384 (identical to NRRL 395 and ATCC 9363) on potato-dextrose-agar medium was studied aiming at starting its L(+)-lactic acid fermentation directly from spore inoculation. Various parameters including harvest time, sowed spore density, size of agar plate, height of air space, and incubation mode of plate (agar-on-bottom or agar-on-top) were studied. Ordinarily used shallow Petri dishes were found out to be unsuitable for the full growth of R. oryzae sporangiophores. In a very wide range of the sowed spore density, the smaller it was, the greater the number of the harvested spores was. It was also interesting to find out that R. oryzae grown downward vertically with a deep air space in an agar-on-top mode gave larger amount of spores than in an agar-on-bottom mode at 30°C for 7-day cultivation. Scale-up of the agar plate culture from 26.4 to 292 cm(2) was studied, resulting in the proportional relationship between the number of the harvested spores/plate and the plate area in the deep Petri dishes. The number of plates of 50 cm in diameter needed for 100 m(3) industrial submerged fermentation started directly from 2 × 10(5) spores/mL inoculum size was estimated as about 6, from which it was inferred that such a fermentation would be feasible. Designing a 50 cm plate and a method of spreading and collecting the spores were suggested. Bioprocess technological significance of the "full-scale industrial submerged fermentation started directly from spore inoculation omitting pre-culture" has been discussed. © 2013 American Institute of Chemical Engineers.

  7. Recovery of DNA from agarose gel by trap method | Xia | African ...

    African Journals Online (AJOL)

    Recovery of DNA from agarose gel electrophoresis is a basic operation during molecular cloning. Circular or linear DNA fragments which vary from 1.5 to 6.5 kb and correspond to 1 kb marker can be recovered from 0.8 to 1.0% agarose gel smoothly with a simple and rapid trap method. The recovery efficiency could be ...

  8. Crosslinked agarose encapsulated sorbents resistant to steam sterilization. Preparation and mechanical properties

    NARCIS (Netherlands)

    de Koning, H. W.; Chamuleau, R. A.; Bantjes, A.

    1984-01-01

    The application of agarose in hemoperfusion is hampered by the lack of a suitable sterilization method. A technique has been developed for the crosslinking of agarose encapsulated sorbents by the reaction with 1,3-dichloro-2-propanol (DCP) under strong alkaline conditions. A twofold molar excess of

  9. Bleach gel: a simple agarose gel for analyzing RNA quality.

    Science.gov (United States)

    Aranda, Patrick S; LaJoie, Dollie M; Jorcyk, Cheryl L

    2012-01-01

    RNA-based applications requiring high-quality, non-degraded RNA are a foundational element of many research studies. As such, it is paramount that the integrity of experimental RNA is validated prior to cDNA synthesis or other downstream applications. In the absence of expensive equipment such as microfluidic electrophoretic devices, and as an alternative to the costly and time-consuming standard formaldehyde gel, RNA quality can be quickly analyzed by adding small amounts of commercial bleach to TAE buffer-based agarose gels prior to electrophoresis. In the presence of low concentrations of bleach, the secondary structure of RNA is denatured and potential contaminating RNases are destroyed. Because of this, the 'bleach gel' is a functional approach that addresses the need for an inexpensive and safe way to evaluate RNA integrity and will improve the ability of researchers to rapidly analyze RNA quality. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Growth in Agarose of Human Cells Infected with Cytomegalovirus

    Science.gov (United States)

    Lang, David J.; Montagnier, Luc; Latarjet, Raymond

    1974-01-01

    After infection by human cytomegalovirus (CMV), human diploid fibroblasts could grow in agarose medium for several generations. Clones of infected cells grew for weeks, although in every case they ultimately underwent lysis owing to the cytopathic effect of the virus. Virus was inoculated at high dilution and after UV irradiation in an effort to derive cells infected with noninfectious defective particles still capable of inducing cell stimulation. Dilute or irradiated virus occasionally yielded large colonies of replicating cells, although permanent transformation was not observed. One clone derived from UV-CMV-infected cells was passaged four times before undergoing lysis. During these passages the cells exhibited alterations in morphology and orientation. Images PMID:4367907

  11. Thermoresponsive chitosan-agarose hydrogel for skin regeneration.

    Science.gov (United States)

    Miguel, Sónia P; Ribeiro, Maximiano P; Brancal, Hugo; Coutinho, Paula; Correia, Ilídio J

    2014-10-13

    Healing enhancement and pain control are critical issues on wound management. So far, different wound dressings have been developed. Among them, hydrogels are the most applied. Herein, a thermoresponsive hydrogel was produced using chitosan (deacetylation degree 95%) and agarose. Hydrogel bactericidal activity, biocompatibility, morphology, porosity and wettability were characterized by confocal microscopy, MTS assay and SEM. The performance of the hydrogel in the wound healing process was evaluated through in vivo assays, during 21 days. The attained results revealed that hydrogel has a pore size (90-400 μm) compatible with cellular internalization and proliferation. A bactericidal activity was observed for hydrogels containing more than 188 μg/mL of chitosan. The improved healing and the lack of a reactive or a granulomatous inflammatory reaction in skin lesions treated with hydrogel demonstrate its suitability to be used in a near future as a wound dressing. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Preparation of gold nanoparticles-agarose gel composite and its application in SERS detection.

    Science.gov (United States)

    Ma, Xiaoyuan; Xia, Yu; Ni, Lili; Song, Liangjing; Wang, Zhouping

    2014-01-01

    Agarose gel/gold nanoparticles hybrid was prepared by adding gold nanoparticles to preformed agarose gel. Nanocomposite structures and properties were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and UV-Vis-NIR absorption spectroscopy. Based on the swelling-contraction characteristics of agarose gel and the adjustable localized surface plasmon resonance (LSPR) of the gold nanoparticles, the nanocomposites were used as surface enhanced Raman scattering (SERS) substrate to detect the Raman signal molecules (NBA, MBA, 1NAT). Results revealed that the porous structure of the agarose gel provided a good carrier for the enrichment of the gold nanoparticles. The gold nanoparticles dynamic hot-spot effect arising from the agarose gel contraction loss of water in the air greatly enhanced the Raman signal. Furthermore, the gel could be cleaned with washing solution and recycling could be achieved for Raman detection. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Unraveling the nuclear and chloroplast genomes of an agar producing red macroalga, Gracilaria changii (Rhodophyta, Gracilariales).

    Science.gov (United States)

    Ho, Chai-Ling; Lee, Wei-Kang; Lim, Ee-Leen

    2018-03-01

    Agar and agarose have wide applications in food and pharmaceutical industries. Knowledge on the genome of red seaweeds that produce them is still lacking. To fill the gap in genome analyses of these red algae, we have sequenced the nuclear and organellar genomes of an agarophyte, Gracilaria changii. The partial nuclear genome sequence of G. changii has a total length of 35.8Mb with 10,912 predicted protein coding sequences. Only 39.4% predicted proteins were found to have significant matches to protein sequences in SwissProt. The chloroplast genome of G. changii is 183,855bp with a total of 201 open reading frames (ORFs), 29 tRNAs and 3 rRNAs predicted. Five genes: ssrA, leuC and leuD CP76_p173 (orf139) and pbsA were absent in the chloroplast genome of G. changii. The genome information is valuable in accelerating functional studies of individual genes and resolving evolutionary relationship of red seaweeds. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Palm kernel agar: An alternative culture medium for rapid detection ...

    African Journals Online (AJOL)

    The feasibility of using palm kernel agar (PKA) as an alternative culture medium to desiccated coconut agar (DCA), the conventional medium for the recovery of aflatoxigenic fungi from mixed cultures and the detection of aflatoxigenic fungi and direct visual determination of aflatoxins in agricultural commodities was ...

  15. Methods for identifying lipoxygenase producing microorganisms on agar plates

    NARCIS (Netherlands)

    Nyyssola, A.; Heshof, R.; Haarmann, T.; Eidner, J.; Westerholm-Parvinen, A.; Langfelder, K.; Kruus, K.; Graaff, de L.H.; Buchert, J.

    2012-01-01

    Plate assays for lipoxygenase producing microorganisms on agar plates have been developed. Both potassium iodide-starch and indamine dye formation methods were effective for detecting soybean lipoxygenase activity on agar plates. A positive result was also achieved using the beta-carotene bleaching

  16. Seasonal variations of agar extracted from different life stages of ...

    African Journals Online (AJOL)

    Seasonality in yield, physical and chemical properties of the native agar from different life stages of Gracilaria cliftonii was investigated over a period of six seasons (autumn 2008–winter 2009). Agar yield and its properties varied as a function of seasons and life stages but there was no significant correlation between ...

  17. Assessment of Native Agar Gels Extracted from Gracilaria debilis ...

    African Journals Online (AJOL)

    Native agar gels extracted from Gracilaria debilis and G. salicornia harvested during the rainy and dry seasons, were assessed for culturing the microorganisms Micrococcus luteus, Saccharomyces cerevisiae and Pleurotus flabellatus. Agars extracted from plants harvested during the rainy season were suitable for culturing ...

  18. Extracción, identificación y prueba microbiológica del agar extraído de Gracilaria fortissima dawson (rhodophyta, gigartinales, gracilariaceae (ING

    Directory of Open Access Journals (Sweden)

    M.V. Sánchez

    2016-03-01

    Full Text Available The red seaweed Gracilaria fortissima colected in the caribean coast of Costa Rica, was studied for the extraction, identification and microbiological performance of the agar contend of this plant, as well as the mineral contend. The research was done focused on the agar quality included pH, % extraction, geling point, fusion point and gel strength, as well as infrared analysis and the performance as a microbiological culture of bacteria and fungus and compared with commercial agar from BDH chemicals.

  19. Methods of high integrity RNA extraction from cell/agarose construct.

    Science.gov (United States)

    Ogura, Takahiro; Tsuchiya, Akihiro; Minas, Tom; Mizuno, Shuichi

    2015-11-04

    Agarose hydrogels are widely used for three-dimensional cell scaffolding in tissue engineering and cell biology. Recently, molecular profiles have been obtained with extraction of a minimal volume of RNA using fluorescent-tagged quantitative polymerase chain reaction (qPCR), which requires high integrity RNA. However, the agarose interferes considerably with the quantity and quality of the extracted RNA. Moreover, little is known about RNA integrity when the RNA is extracted from cell/agarose construct. Thus, in order to obtain RNA of sufficient integrity, we examined various extraction methods and addressed reproducible methodologies for RNA extraction from cell/agarose constructs using spectrophotometry and microfluidic capillary electrophoresis. With various extraction methods using a mono-phasic solution of phenol and guanidine isothiocyanate, we evaluated quantity and quality of total RNA from cell/agarose construct. Extraction with solution of phenol and guanidine isothiocyanate followed by a silica based membrane filter column gave sufficient RNA integrity number, which allowed us to proceed to fluorescent-tagged qPCR for evaluating various cellular activities. The RNA extraction methods using phenol and guanidine isothiocyanate solution and a silica membrane column can be useful for obtaining high integrity RNA from cell/agarose constructs rich in polysaccharide and extracellular matrix. Our study contributes to further investigation using agarose hydrogels and other materials rich in polysaccharide in the field of cellular and tissue engineering.

  20. Cost-effectiveness of blood agar for isolation of mycobacteria.

    Directory of Open Access Journals (Sweden)

    Michel Drancourt

    Full Text Available BACKGROUND: Mycobacterium species are grown using specific media that increase laboratory cost, thus hampering their diffusion in resource-limited countries. Preliminary data suggested that versatile blood agar may be also used for mycobacterial culture. METHODOLOGY: We examined the growth of 41 different Mycobacterium species on 5% blood agar. Over a 24-month period we analysed isolation of mycobacteria after parallel inoculation of clinical specimens into both a reference automated system (BACTEC 9000 MB broth and 5% blood agar slant tubes, after NaOH decontamination, and compared the cost of performing 1,000 analyses using these two techniques. CONCLUSIONS: Mycobacterium reference species cultured on blood agar, with the exception of Mycobacterium ulcerans. Inoculation of 1,634 specimens yielded 95 Mycobacterium isolates. Blood agar performed significantly more efficiently than BACTEC 9000 MB broth (94 vs 88 isolates, P = 0.03. Decontamination of Candida albicans in 5 specimens by addition of amphotericin B in blood agar yielded one more M. tuberculosis isolate that could not be isolated in BACTEC broth. Uneven distribution of time to culture positivity for M. tuberculosis had a median (range of 19+/-5 days using blood agar and 26+/-6 days using BACTEC 9000 MB broth. Cost for 1,000 analyses in France was estimated to be of 1,913 euros using the blood agar method and 8,990 euros using the BACTEC 9000 MB method. Blood agar should be regarded as a first-line medium for culturing Mycobacterium species. It saves time, is cost-effective, is more sensitive than, and at least as rapid as the automated method. This is of particular importance for resource-limited countries in which the prevalence of tuberculosis is high.

  1. Evolutionary consequences of putative intra- and interspecific hybridiation in agaric fungi

    Science.gov (United States)

    Karen W. Hughes; Ronald H. Petersen; D. Jean Lodge; Sarah E. Bergemann; Kendra Baumgartner; Rodham E. Tulloss; Edgar Lickey; Joaquin. Cifuentes

    2013-01-01

    Agaric fungi of the southern Appalachian Mountains including Great Smoky Mountains National Park are often heterozygous for the rDNA internal transcribed spacer region (ITS) with .42% of collections showing some heterozygosity for indels and/or base-pair substitutions. For these collections, intra-individual haplotype divergence is typically less than 2%, but for 3% of...

  2. Can serums be replaced by Mueller‑Hinton agar in germ tube test?

    African Journals Online (AJOL)

    2016-03-03

    Mar 3, 2016 ... various serums (i.e., human, rabbit, horse, and fetal bovine serum) used in the GTT and Mueller‑Hinton agar (MHA). Materials and Methods: Fifty species isolated from various clinical samples that were defined as C. albicans by both conventional and DNA sequence analysis methods were included in the ...

  3. Distributed vasculogenesis from modular agarose-hydroxyapatite-fibrinogen microbeads.

    Science.gov (United States)

    Rioja, Ana Y; Daley, Ethan L H; Habif, Julia C; Putnam, Andrew J; Stegemann, Jan P

    2017-06-01

    Critical limb ischemia impairs circulation to the extremities, causing pain, disrupted wound healing, and potential tissue necrosis. Therapeutic angiogenesis seeks to repair the damaged microvasculature directly to restore blood flow. In this study, we developed modular, micro-scale constructs designed to possess robust handling qualities, allow in vitro pre-culture, and promote microvasculature formation. The microbead matrix consisted of an agarose (AG) base to prevent aggregation, combined with cell-adhesive components of fibrinogen (FGN) and/or hydroxyapatite (HA). Microbeads encapsulating a co-culture of human umbilical vein endothelial cells (HUVEC) and fibroblasts were prepared and characterized. Microbeads were generally 80-100µm in diameter, and the size increased with the addition of FGN and HA. Addition of HA increased the yield of microbeads, as well as the homogeneity of distribution of FGN within the matrix. Cell viability was high in all microbead types. When cell-seeded microbeads were embedded in fibrin hydrogels, HUVEC sprouting and inosculation between neighboring microbeads were observed over seven days. Pre-culture of microbeads for an additional seven days prior to embedding in fibrin resulted in significantly greater HUVEC network length in AG+HA+FGN microbeads, as compared to AG, AG+HA or AG+FGN microbeads. Importantly, composite microbeads resulted in more even and widespread endothelial network formation, relative to control microbeads consisting of pure fibrin. These results demonstrate that AG+HA+FGN microbeads support HUVEC sprouting both within and between adjacent microbeads, and can promote distributed vascularization of an external matrix. Such modular microtissues may have utility in treating ischemic tissue by rapidly re-establishing a microvascular network. Critical limb ischemia (CLI) is a chronic disease that can lead to tissue necrosis, amputation, and death. Cell-based therapies are being explored to restore blood flow and

  4. AGAR PENULISAN RESEP TETAP UP TO DATE

    Directory of Open Access Journals (Sweden)

    Rahmatini Rahmatini

    2009-09-01

    Full Text Available AbstrakResep adalah suatu permintaan tertulis dari dokter, dokter gigi atau dokter hewan kepada apoteker untuk membuatkan obat dalam bentuk sediaan tertentu dan menyerahkannya kepada pasien. Resep merupakan perwujudan akhir dari kompetensi, pengetahuan dan keahlian dokter dalam menerapkan pengetahuannya dalam bidang farmakologi dan terapi.Penulisan resep harus ditulis dengan jelas sehingga dapat dibaca oleh petugas di apotek. Resep yang ditulis dengan tidak jelas akan menimbulkan terjadinya kesalahan saat peracikan / penyiapan obat dan penggunaan obat yang diresepkan.Ilmu pengetahuan tentang obat selalu berubah, obat – obat baru selalu muncul di pasaran.Secara umum, seorang dokter harus mengikuti perkembangan dalam terapi obat. Bila muncul efek samping akibat obat yang seharusnya diketahui dan dapat dicegah oleh dokter, maka dokter akan berhadapan dengan hukum.Agar penulisan resep tetap up to date, seorang dokter harus mengumpulkan berbagai informasi yang tersedia. Sumber informasi yang dapat digunakan adalah : Buku acuan, Kompendium obat, Daftar Obat Esensial Nasional (DOEN dan Pedoman terapi, Buletin obat, Jurnal Kedokteran, Pusat informasi obat,Informasi melalui komputer, Sumber informasi dari industri farmasi, dan informasi lisan.Bandingkan kelebihan dan kekurangan berbagai sumber informasi. Tugas seorang dokter adalah melakukan cara terbaik untuk tetap up to date dengan mendaftar sumber informasi yang dapat dimanfaatkan. Carilah sedikitnya satu dari yang berikut ini : (1 jurnal kedokteran: (2 buletin obat; (3 buku acuan farmakologi atau acuan klinis; (4 komisi terapi maupun konsultan, atau lulusan pasca sarjana farmakologi. Dengan bekal pengetahuan dan kemampuan untuk melakukan penilaian secara kritis setiap bentuk informasi, diharapkan dokter tetap up to date dalam menulis resepKata kunci : Resep – up to- date.Abstract Prescription is a written request from a doctor, dentist or veterinarian to the pharmacist to make a particular drug

  5. Proteoglycon synthesis by articular chondrocytes in agarose culture

    International Nuclear Information System (INIS)

    Sweet, M.B.E.; Grisillo, A.; Coehlo, A.; Schnitzler, C.M.

    1987-01-01

    Articular chondrocytes were isolated from knee joints of full-term bovine foetuses and grown in long-term agarose cultures. At intervals, cultures were labelled with 35 S-[sulphate] or D[6- 3 H] glucosamine. Newly synthesized proteoglycans were extracted with 4 M guanidine HCl and purified by isopycnic density gradient centrifugation or on DEAE cellulose in the presence of 8 M urea. Characterization of the proteoglycans revealed them to be identical in size to those present in the tissue and to be similarly capable of aggregation with hyaluronate. Newly synthesized chondroitin sulphate chains were identical in size, but newly synthesized keratan sulphate chains were somewhat larger than those present in the tissue. The newly synthesized proteoglycans were shown to contain the same range of O-linked oligosaccharides identified in proteoglycans of the Swarm rat chondrosarcoma. Cartilage-specific proteoglycan continued to be synthesized by the chondrocytes for up to 60 days; however, with time, proportionately more of a small non-aggregating proteoglycan appeared

  6. Suitability of various plant derived gelling agents as agar substitute ...

    African Journals Online (AJOL)

    Suitability of various plant derived gelling agents as agar substitute in microbiological growth media. Abdul Mateen, Shaukat Hussain, Shams Ur Rehman, Basharat Mahmood, Muhammad Aslam Khan, Abdul Rashid, Majid Sohail, Muhammad Farooq, S Jawad Ahmed Shah ...

  7. History and environmental education- A review of agar's thesis with ...

    African Journals Online (AJOL)

    History has a major contribution to make to the understanding of the present day environment, and consequently a significcnt role to play in environmental education. Agar's (1973) arguments for this are reviewed in the context of contemporary Southern Africa.

  8. Detection of extracellular proteases from microorganisms on agar plates

    Directory of Open Access Journals (Sweden)

    Alane Beatriz Vermelho

    1996-12-01

    Full Text Available We present herein an improved assay for detecting the presence of extracellular proteases from microorganisms on agar plates. Using different substrates (gelatin, BSA, hemoglobin incorporated into the agar and varying the culture medium composition, we were able to detect proteolytic activities from Pseudomonas aeruginosa, Micrococcus luteus and Serratia marcescens as well as the influence that these components displayed in the expression of these enzymes. For all microorganisms tested we found that in agar-BHI or yeast extract medium containing gelatin the sensitivity of proteinase detection was considerably greater than in BSA-agar or hemoglobin-agar. However, when BSA or hemoglobin were added to the culture medium, there was an increase in growth along with a marked reduction in the amount of proteinase production. In the case of M. luteus the incorporation of glycerol in BHI or yeast extract gelatin-agar induced protease liberation. Our results indicate that the technique described here is of value for detecting extracellular proteases directly in the culture medium, by means of a qualitative assay, simple, inexpensive, straight forward method to assess the presence of the proteolytic activity of a given microorganism colony with great freedom in substrate selection.

  9. Thallium toxicosis in a dog consequent to ingestion of Mycoplasma agar plates.

    Science.gov (United States)

    Puschner, Birgit; Basso, Marguerite M; Graham, Thomas W

    2012-01-01

    A 1-year-old dog ingested a mixture of blood agar and Mycoplasma agar plates. The Mycoplasma agar plates contained thallium acetate, which resulted in an estimated minimum dose of 5 mg thallium acetate/kg bodyweight. Clinical signs over the course of 2-3 weeks included vomiting, diarrhea, weight loss, alopecia, dysphonia, ataxia, paresthesia, intension tremors, megaesophagus with subsequent aspiration pneumonia, and several seizure episodes. The dog was treated with intravenous fluids and placement of a gastric feeding tube. Thallium concentrations in hair were 8.2 µg/g in samples taken on day 19, 16.4 µg/g in samples taken 3 months after exposure, 13.4 µg/g in samples taken 5 months after exposure, and nondetectable in samples taken 7 months after exposure. The blood thallium concentration was 190 µg/l on day 19 and nondetec table 3 months after exposure. Megaesophagus and dysphonia continued for 10 months after exposure. This case of thallium poisoning following ingestion of mycoplasma agar plates demonstrates that unusual sources of thallium still exist and suggests that thallium toxicosis should be included in the list of differential diagnoses in dogs presented with megaesophagus, especially if alopecia and other unexplained peripheral neuropathies are present. Hair and blood samples are useful specimens to reach an accurate diagnosis even if taken several weeks post exposure. The postexposure blood and hair thallium concentrations reported in this case are useful data for diagnosticians investigating dogs with potential thallium poisoning.

  10. Films of Agarose Enable Rapid Formation of Giant Liposomes in Solutions of Physiologic Ionic Strength

    OpenAIRE

    Horger, Kim S.; Estes, Daniel J.; Capone, Ricardo; Mayer, Michael

    2009-01-01

    This paper describes a method to form giant liposomes in solutions of physiologic ionic strength, such as phosphate buffered saline (PBS) or 150 mM KCl. Formation of these cell-sized liposomes proceeded from hybrid films of partially dried agarose and lipids. Hydrating the films of agarose and lipids in aqueous salt solutions resulted in swelling and partial dissolution of the hybrid films and in concomitant rapid formation of giant liposomes in high yield. This method did not require the pre...

  11. A comparison of EF-18 agar and modified brilliant green agar with lutensit for isolation of Salmonella from poultry samples

    DEFF Research Database (Denmark)

    Petersen, Line Hedegård

    1997-01-01

    -Vassiliadis broth, and 3) Plating onto EF-18 agar and BGA/L simultaneously. From a total of 1101 samples, Salmonella was isolated from 158, 157 of which were faecal samples. Thirtyone of these isolates were recovered on one medium only, 18 could not be found on BGA/L and 13 could not be found on EF-18 agar....... The relative specificity and sensitivity of each plating agar was determined by enumeration of false-positive and false-negative reactions. EF-18 agar compared favourably with BGA/L, displaying a sensitivity of 0.92 as opposed to 0.89 for BGA/L, calculated for the ''fecal samples'' group only. The calculated...... specificities for each group of samples were likewise considerably higher for EF-18 agar (0.75-0.91) than for BGA/L (0.35-0.55). Though EF-18 agar is slightly more expensive than BGA/L, the routine use of the former may result in a considerable reduction in overall laboratory costs due to its superior...

  12. Reconstructing the evolution of agarics from nuclear gene sequences and basidiospore ultrastructure.

    Science.gov (United States)

    Garnica, Sigisfredo; Weiss, Michael; Walther, Grit; Oberwinkler, Franz

    2007-09-01

    Traditional classifications of agaric fungi involve gross morphology of their fruit bodies and meiospore print-colour. However, the phylogeny of these fungi and the evolution of their morphological and ecological traits are poorly understood. Phylogenetic analyses have already demonstrated that characters used in traditional classifications of basidiomycetes may be heavily affected by homoplasy, and that non-gilled taxa evolved within the agarics several times. By integrating molecular phylogenetic analyses including domains D1-D3 and D7-D8 of nucLSU rDNA and domains A-C of the RPB1 gene with morphological and chemical data from representative species of 88 genera, we were able to resolve higher groups of agarics. We found that the species with thick-walled and pigmented basidiospores constitute a derived group, and hypothesize that this specific combination of characters represents an evolutionary advantage by increasing the tolerance of the basidiospores to dehydration and solar radiation and so opened up new ecological niches, e.g. the colonization of dung substrates by enabling basidiospores to survive gut passages through herbivores. Our results confirm the validity of basidiospore morphology as a phylogenetic marker in the agarics.

  13. Observing Chemotaxis in Vibrio fischeri Using Soft Agar Assays in an Undergraduate Microbiology Laboratory

    Directory of Open Access Journals (Sweden)

    Cindy R. DeLoney-Marino

    2013-08-01

    Full Text Available Chemotaxis, the directed movement of cells towards or away from a chemical, is both an exciting and complicated behavior observed in many bacterial species. Attempting to adequately visualize or demonstrate the chemotaxic response of bacteria in the classroom is difficult at best, with good models to illustrate the concept lacking. The BSL-1 marine bacterium Vibrio fischeri (a.k.a. Aliivibrio fischeri is easy to culture, making it an ideal candidate for experiments in an undergraduate microbiology course. A number of chemoattractants for V. fischeri have been identified, including a variety of sugars, nucleosides, and amino acids (1, 2. Below presents how the soft agar-based chemotaxis assay can be implemented in the undergraduate laboratory. As bacterial cells migrate towards one or more attractants in soft agar, students can directly observe the chemotaxic behavior of V. fischeri without the need to learn complicated techniques or use specialized equipment. Once the bands of bacterial cells are observed, the migration can then be disrupted by the addition of excess attractant to the soft agar, thereby visualizing what happens once cells are no longer in a gradient of attractant. In addition, soft agar plates lacking attractants can be used to visualize the random movements of bacterial cells that are non-chemotaxing. These exercises can be used in the microbiology laboratory to help students understand the complex behavior of bacterial chemotaxis.

  14. Use of the Soft-agar Overlay Technique to Screen for Bacterially Produced Inhibitory Compounds.

    Science.gov (United States)

    Hockett, Kevin L; Baltrus, David A

    2017-01-14

    The soft-agar overlay technique was originally developed over 70 years ago and has been widely used in several areas of microbiological research, including work with bacteriophages and bacteriocins, proteinaceous antibacterial agents. This approach is relatively inexpensive, with minimal resource requirements. This technique consists of spotting supernatant from a donor strain (potentially harboring a toxic compound(s)) onto a solidified soft agar overlay that is seeded with a bacterial test strain (potentially sensitive to the toxic compound(s)). We utilized this technique to screen a library of Pseudomonas syringae strains for intraspecific killing. By combining this approach with a precipitation step and targeted gene deletions, multiple toxic compounds produced by the same strain can be differentiated. The two antagonistic agents commonly recovered using this technique are bacteriophages and bacteriocins. These two agents can be differentiated using two simple additional tests. Performing a serial dilution on a supernatant containing bacteriophage will result in individual plaques becoming less in number with greater dilution, whereas serial dilution of a supernatant containing bacteriocin will result a clearing zone that becomes uniformly more turbid with greater dilution. Additionally, a bacteriophage will produce a clearing zone when spotted onto a fresh soft agar overlay seeded with the same strain, whereas a bacteriocin will not produce a clearing zone when transferred to a fresh soft agar lawn, owing to the dilution of the bacteriocin.

  15. Agar/collagen membrane as skin dressing for wounds

    International Nuclear Information System (INIS)

    Bao Lei; Yang Wei; Mao Xuan; Mou Shansong; Tang Shunqing

    2008-01-01

    Agar, a highly hydrophilic polymer, has a special gel property and favorable biocompatibility, but moderate intension strength in an aqueous condition and a low degradation rate. In order to tailor both properties of mechanical intension and degradation, type I collagen was composited with agar in a certain ratio by drying at 50 0 C or by a freeze-dry process. Glutaraldehyde was chosen as a crosslinking agent, and the most favorable condition for crosslinking was that the weight ratio of agar to glutaraldehyde was 66.7 and the pH value about 5. Dynamic mechanical analysis results showed that the single agar membrane had a modulus value between 640 MPa and 1064 MPa, but it was between 340 MPa and 819 MPa after being composited with type I collagen. It was discovered under an optical microscope that the pores were interconnected in the composite scaffolds instead of the honeycomb-like pores in a single type I collagen scaffold or the laminated gaps in a single agar scaffold. The results of an acute toxicity test disclosed that the composites were not toxic to mice although the composites were crosslinked with a certain concentration of glutaraldehyde. The results of gross examinations showed that when the composite membranes or scaffolds were applied to a repair rabbit skin lesion, the composites had a good repair effect without infection, liquid exudation or visible scar in the lesion covered with them. But in the control group, the autologous skin showed necrosis and there were a lot of scar tissues in the lesion site. H and E staining results showed that the repair tissue was similar to the normal one and very few scaffolds or membranes were left without degradation after 2 or 3 weeks. In conclusion, it is proved that type I collagen increases the toughness of the agar membrane, and the agar/type I collagen composites are promising biomaterials as wound dressings for healing burns or ulcers.

  16. Egg yolk emulsion agar, a new medium for the cultivation of Helicobacter pylori.

    OpenAIRE

    Westblom, T U; Madan, E; Midkiff, B R

    1991-01-01

    We developed a new agar, egg yolk emulsion (EYE) agar, for cultivation of Helicobacter pylori. EYE agar contains Columbia agar base (Oxoid), 10% EYE (Oxoid), 1% IsoVitaleX (BBL), and 40 mg of Triphenyleteraxolium chloride (Sigma) per liter. We compared EYE agar with the following agars: (i) brain heart infusion agar-7% horse blood-1% IsoVitaleX (GDW agar; C. S. Goodwin, E. D. Blincow, J. R. Warren, T. E. Waters, C. R. Sanderson, and L. Easton, J. Clin. Pathol. 38:1127-1131, 1985), (ii) brain ...

  17. Retention of gene expression in porcine islets after agarose encapsulation and long-term culture

    Energy Technology Data Exchange (ETDEWEB)

    Dumpala, Pradeep R., E-mail: pdumpala@rixd.org [The Rogosin Institute – Xenia Division, 740 Birch Road, Xenia, OH 45385 (United States); Holdcraft, Robert W.; Martis, Prithy C.; Laramore, Melissa A. [The Rogosin Institute – Xenia Division, 740 Birch Road, Xenia, OH 45385 (United States); Parker, Thomas S.; Levine, Daniel M. [The Rogosin Institute, 505 East 70th Street, New York, NY 10021 (United States); Smith, Barry H. [The Rogosin Institute, 505 East 70th Street, New York, NY 10021 (United States); NewYork-Presbyterian Hospital, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021 (United States); Gazda, Lawrence S. [The Rogosin Institute – Xenia Division, 740 Birch Road, Xenia, OH 45385 (United States)

    2016-08-05

    Agarose encapsulation of porcine islets allows extended in vitro culture, providing ample time to determine the functional capacity of the islets and conduct comprehensive microbiological safety testing prior to implantation as a treatment for type 1 diabetes mellitus. However, the effect that agarose encapsulation and long-term culture may have on porcine islet gene expression is unknown. The aim of the present study was to compare the transcriptome of encapsulated porcine islets following long-term in vitro culture against free islets cultured overnight. Global gene expression analysis revealed no significant change in the expression of 98.47% of genes. This indicates that the gene expression profile of free islets is highly conserved following encapsulation and long-term culture. Importantly, the expression levels of genes that code for critical hormones secreted by islets (insulin, glucagon, and somatostatin) as well as transcripts encoding proteins involved in their packaging and secretion are unchanged. While a small number of genes known to play roles in the insulin secretion and insulin signaling pathways are differentially expressed, our results show that overall gene expression is retained following islet isolation, agarose encapsulation, and long-term culture. - Highlights: • Effect of agarose encapsulation and 8 week culture on porcine islets was analyzed. • Transcriptome analysis revealed no significant change in a majority (98%) of genes. • Agarose encapsulation allows for long-term culture of porcine islets. • Islet culture allows for functional and microbial testing prior to clinical use.

  18. Agarose overlay selectively improves macrocolony formation and radiosensitivity assessment in primary fibroblasts.

    Science.gov (United States)

    Chandna, Sudhir; Dagur, Raghubendra Singh; Mathur, Ankit; Natarajan, Adayapalam Tyagarajan; Harms-Ringdahl, Mats; Haghdoost, Siamak

    2014-05-01

    Primary fibroblasts are not suitable for in vitro macrocolony assay due to their inability to form distinct colonies. Here we present a modification of agarose overlay that yielded extensive improvement in their colony formation and assessment of radiosensitivity. Macrocolony formation was assessed in primary human fibroblasts VH10 and HDFn with or without overlay using 0.5% agarose in growth medium at 24 h post-seeding. Malignant human cell lines (A549, U87) and transformed non-malignant fibroblasts (AA8 hamster, MRC5 human) were used for comparison. Agarose overlay caused significant improvement marked by early appearance (one week) of distinct colonies with high cell density and multifold higher plating efficiency than conventional macrocolony assay in VH10 and HDFn human fibroblasts. Compared to conventional assay or feeder cell supplementation, agarose overlay resulted in broader cell morphology due to improved adherence, and yielded more compact colonies. Gamma-radiation dose-response survival curves could be successfully generated for both fibroblast cell lines using this method, which yielded no such effects in the transformed/malignant cell lines tested. This easy and inexpensive 'agarose overlay technique' significantly and selectively improves the fibroblast plating efficiency, thus considerably reducing time and effort to greatly benefit the survival studies on primary fibroblasts.

  19. Retention of gene expression in porcine islets after agarose encapsulation and long-term culture

    International Nuclear Information System (INIS)

    Dumpala, Pradeep R.; Holdcraft, Robert W.; Martis, Prithy C.; Laramore, Melissa A.; Parker, Thomas S.; Levine, Daniel M.; Smith, Barry H.; Gazda, Lawrence S.

    2016-01-01

    Agarose encapsulation of porcine islets allows extended in vitro culture, providing ample time to determine the functional capacity of the islets and conduct comprehensive microbiological safety testing prior to implantation as a treatment for type 1 diabetes mellitus. However, the effect that agarose encapsulation and long-term culture may have on porcine islet gene expression is unknown. The aim of the present study was to compare the transcriptome of encapsulated porcine islets following long-term in vitro culture against free islets cultured overnight. Global gene expression analysis revealed no significant change in the expression of 98.47% of genes. This indicates that the gene expression profile of free islets is highly conserved following encapsulation and long-term culture. Importantly, the expression levels of genes that code for critical hormones secreted by islets (insulin, glucagon, and somatostatin) as well as transcripts encoding proteins involved in their packaging and secretion are unchanged. While a small number of genes known to play roles in the insulin secretion and insulin signaling pathways are differentially expressed, our results show that overall gene expression is retained following islet isolation, agarose encapsulation, and long-term culture. - Highlights: • Effect of agarose encapsulation and 8 week culture on porcine islets was analyzed. • Transcriptome analysis revealed no significant change in a majority (98%) of genes. • Agarose encapsulation allows for long-term culture of porcine islets. • Islet culture allows for functional and microbial testing prior to clinical use.

  20. Preparation of Agar-Agar from the Red Seaweed Pterocladia capillacea off the Coast of Alexandria, Egypt.

    Science.gov (United States)

    Rao, A V; Bekheet, I A

    1976-10-01

    The effect of different treatments on the quality of agar produced from Pterocladia has been studied, and the conditions for the production of material of good quality have been standardized. In the modified process, sun-bleached seaweed was washed well in water, soaked for 24 h, and then ground to a pulp and rinsed again in water. The pulp was then extracted with water (weed-to-water ratio, 1:30) under pressure for 2 h after adjusting the pH to 6 by the addition of acetic acid. The agar gel, after freeze thawing, was bleached with NaClO before drying in a current of hot air. Pretreatment of the seaweed with alkali at 80 degrees C for 2 h prior to extraction was found to improve the quality of agar to a very great extent.

  1. Comparison of Six Chromogenic Agar Media for the Isolation of a Broad Variety of Non-O157 Shigatoxin-Producing Escherichia coli (STEC) Serogroups

    Science.gov (United States)

    Verhaegen, Bavo; De Reu, Koen; Heyndrickx, Marc; De Zutter, Lieven

    2015-01-01

    The isolation of non-O157 STEC from food samples has proved to be challenging. The selection of a suitable selective isolation agar remains problematic. The purpose of this study was to qualitatively and quantitatively evaluate six chromogenic agar media for the isolation of STEC: Tryptone Bile X-glucuronide agar (TBX), Rainbow® Agar O157 (RB), Rapid E. coli O157:H7 (RE), Modified MacConkey Agar (mMac), CHROMagarTM STEC (Chr ST) and chromIDTM EHEC (Chr ID). During this study, 45 E. coli strains were used, including 39 STEC strains belonging to 16 different O serogroups and 6 non-STEC E. coli. All E. coli strains were able to grow on TBX and RB, whereas one STEC strain was unable to grow on Chr ID and a number of other STEC strains did not grow on mMac, CHROMagar STEC and Rapid E. coli O157:H7. However, only the latter three agars were selective enough to completely inhibit the growth of the non-STEC E. coli. Our conclusion was that paired use of a more selective agar such as CHROMagar STEC together with a less selective agar like TBX or Chr ID might be the best solution for isolating non-O157 STEC from food. PMID:26090610

  2. Electrolysis induces pH gradients and domain orientation in agarose gels

    Science.gov (United States)

    Michelman-Ribeiro, Ariel; Nossal, Ralph; Morris, Ryan; Lange, Sarah; Kuo, Chein-Shiu; Bansil, Rama

    2006-01-01

    We have used small-angle light-scattering (SALS), microscopy, and pH measurements to study structural changes produced in unbuffered agarose gels as ions migrate under applied electric fields (3-20V/cm) . Anisotropic, bowtielike, light-scattering patterns were observed, whose development occurred more quickly at higher fields. The horizontal lobes were more pronounced at higher polymer concentration. Analysis of the SALS data with a simple model of scattering from anisotropic rods in an electric field is consistent with anisotropic rodlike domains on the order of 10-15μm in length, which align perpendicular to the electric field. The anisotropic domains in the gel reach almost the same level of orientation, regardless of the field strength. Microscope imaging revealed anisotropic domains on the same length scale, also aligned perpendicular to the field. Profiles of pH variation across the gel, measured by video photography, indicate that the anisotropic patterns appear when the H+ and OH- ions, migrating in opposite directions, meet. Calculations of pH profiles using a model based on electrodiffusion reproduce several features of measured pH profiles, including the power-law dependence on the electric field of the time at which the oppositely charged fronts meet. Ions migrating from both ends of the gel produce pH changes that are correlated with macroscopic shrinking and orientation of the gel.

  3. Application of native agarose gel electrophoresis of serum proteins in veterinary diagnostics

    Directory of Open Access Journals (Sweden)

    Jania Bartosz

    2016-12-01

    Full Text Available Electrophoretic techniques, used to separate mixtures of electrically charged particles, are widely used in science. One of these techniques, native protein electrophoresis in an agarose gel, is applied in human and veterinary medicine. Changes in the proportions of individual protein fractions correspond to significant changes in the physiology of the body. Although the pattern obtained by electrophoretic separation rarely indicates a specific disease, it provides valuable information for the differential diagnosis. Decades of research on the types of patterns obtained in the case of particular diseases have led to the accumulation of substantial knowledge. The paper presents the available information on this topic. Serum protein electrophoresis is recommended in cases of increased levels of total protein in order to reveal the nature of the process. The basic information which can be obtained from electrophoretic separation includes the immune status of the organism. Both increased antigenic stimulation and immunodeficiency are clearly visible in electropherograms. Moreover, the level of heterogeneity of the corresponding protein fractions can help to distinguish between infectious diseases and cancer - multiple myeloma - the latter producing a homogeneous immunoglobulin fraction. Analysis of other protein fractions helps to detect or confirm an ongoing inflammatory process and provides information regarding liver function. Even when the concentration of total protein is within the reference range, this analysis can be recommended as a basic laboratory test.

  4. Identification of Cisplatin-Binding Proteins Using Agarose Conjugates of Platinum Compounds

    Science.gov (United States)

    Karasawa, Takatoshi; Sibrian-Vazquez, Martha; Strongin, Robert M.; Steyger, Peter S.

    2013-01-01

    Cisplatin is widely used as an antineoplastic drug, but its ototoxic and nephrotoxic side-effects, as well as the inherent or acquired resistance of some cancers to cisplatin, remain significant clinical problems. Cisplatin's selectivity in killing rapidly proliferating cancer cells is largely dependent on covalent binding to DNA via cisplatin's chloride sites that had been aquated. We hypothesized that cisplatin's toxicity in slowly proliferating or terminally differentiated cells is primarily due to drug-protein interactions, instead of drug-DNA binding. To identify proteins that bind to cisplatin, we synthesized two different platinum-agarose conjugates, one with two amino groups and another with two chlorides attached to platinum that are available for protein binding, and conducted pull-down assays using cochlear and kidney cells. Mass spectrometric analysis on protein bands after gel electrophoresis and Coomassie blue staining identified several proteins, including myosin IIA, glucose-regulated protein 94 (GRP94), heat shock protein 90 (HSP90), calreticulin, valosin containing protein (VCP), and ribosomal protein L5, as cisplatin-binding proteins. Future studies on the interaction of these proteins with cisplatin will elucidate whether these drug-protein interactions are involved in ototoxicity and nephrotoxicity, or contribute to tumor sensitivity or resistance to cisplatin treatment. PMID:23755301

  5. Identification of cisplatin-binding proteins using agarose conjugates of platinum compounds.

    Directory of Open Access Journals (Sweden)

    Takatoshi Karasawa

    Full Text Available Cisplatin is widely used as an antineoplastic drug, but its ototoxic and nephrotoxic side-effects, as well as the inherent or acquired resistance of some cancers to cisplatin, remain significant clinical problems. Cisplatin's selectivity in killing rapidly proliferating cancer cells is largely dependent on covalent binding to DNA via cisplatin's chloride sites that had been aquated. We hypothesized that cisplatin's toxicity in slowly proliferating or terminally differentiated cells is primarily due to drug-protein interactions, instead of drug-DNA binding. To identify proteins that bind to cisplatin, we synthesized two different platinum-agarose conjugates, one with two amino groups and another with two chlorides attached to platinum that are available for protein binding, and conducted pull-down assays using cochlear and kidney cells. Mass spectrometric analysis on protein bands after gel electrophoresis and Coomassie blue staining identified several proteins, including myosin IIA, glucose-regulated protein 94 (GRP94, heat shock protein 90 (HSP90, calreticulin, valosin containing protein (VCP, and ribosomal protein L5, as cisplatin-binding proteins. Future studies on the interaction of these proteins with cisplatin will elucidate whether these drug-protein interactions are involved in ototoxicity and nephrotoxicity, or contribute to tumor sensitivity or resistance to cisplatin treatment.

  6. Mechanical characterisation of agarose-based chromatography resins for biopharmaceutical manufacture.

    Science.gov (United States)

    Nweke, Mauryn C; McCartney, R Graham; Bracewell, Daniel G

    2017-12-29

    Mechanical characterisation of agarose-based resins is an important factor in ensuring robust chromatographic performance in the manufacture of biopharmaceuticals. Pressure-flow profiles are most commonly used to characterise these properties. There are a number of drawbacks with this method, including the potential need for several re-packs to achieve the desired packing quality, the impact of wall effects on experimental set up and the quantities of chromatography media and buffers required. To address these issues, we have developed a dynamic mechanical analysis (DMA) technique that characterises the mechanical properties of resins based on the viscoelasticity of a 1ml sample of slurry. This technique was conducted on seven resins with varying degrees of mechanical robustness and the results were compared to pressure-flow test results on the same resins. Results show a strong correlation between the two techniques. The most mechanically robust resin (Capto Q) had a critical velocity 3.3 times higher than the weakest (Sepharose CL-4B), whilst the DMA technique showed Capto Q to have a slurry deformation rate 8.3 times lower than Sepharose CL-4B. To ascertain whether polymer structure is indicative of mechanical strength, scanning electron microscopy images were also used to study the structural properties of each resin. Results indicate that DMA can be used as a small volume, complementary technique for the mechanical characterisation of chromatography media. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  7. Improved isolation of Vibro vulnificus from seawater and sediment with cellobiose-colistin agar

    DEFF Research Database (Denmark)

    Høi, L.; Dalsgaard, Inger; Dalsgaard, A.

    1998-01-01

    An improved selective medium, cellobiose-colistin (CC) agar, gave a significantly higher (P agar, In a total of 446 alkaline peptone water preenrichments amended...... with polymyxin B, V. vulnificus was isolated from 154 preenrichments (35%) with mCPC agar and from 179 preenrichments (40%) with CC agar. CC agar gave a higher plating efficiency of V. vulnificus cells than did cellobiose-polymyxin B-colistin (CPC) agar, mCPC agar, or thiosulfate-citrate-bile salts-sucrose (TCBS......) agar; the only significant difference was observed with TCBS agar, which gave much lower plating efficiencies than the other selective media. Determination of MICs demonstrated that the concentrations of colistin and polymyxin B in CPC agar inhibit growth of a proportion of V. vulnificus strains....

  8. Assessment of Native Agar Gels Extracted from Gracilaria debilis ...

    African Journals Online (AJOL)

    PhD thesis. University of Dar es Salaam. Buriyo, A.S. & Kivaisi, A.K. (2003) Standing stock, agar yield and properties of Gracilaria salicornia harvested along the Tanzanian coast. Western. Indian Ocean J. Mar. Sci. 2: 171-178. Buriyo, A. S., Oliveira, E. C., Mtolera, M. S. P. &. Kivaisi, A. K. (2004). Taxonomic challenges and.

  9. Rheological properties of agar and carrageenan from Ghanaian red seaweeds

    DEFF Research Database (Denmark)

    Rhein-Knudsen, Nanna; Ale, Marcel Tutor; Ajalloueian, Fatemeh

    2017-01-01

    Red seaweeds contain unique galactose-rich hydrocolloids, carrageenans and agar, which find use as gelling agents in high value applications. This study examined the chemical and rheological properties of hydrocolloids from selected wild red seaweed species collected in Ghana: Hypnea musciformis ...

  10. How selective are agar cultures for malignant transformation?

    NARCIS (Netherlands)

    Klein, J.C.

    1981-01-01

    In vitro assays that permit cloning of tumour cells in soft agar have been improved during the last 5 years. Two of them are claimed to be useful as test systems for the screening of new anticancer drugs and even for drug sensitivity testing of individual human tumours in devising individualized

  11. Quantitative determination of glycine in aqueous solution using glutamate dehydrogenase-immobilized glyoxal agarose beads.

    Science.gov (United States)

    Keskin, Semra Yilmazer; Keskin, Can Serkan

    2014-01-01

    In this study, an enzymatic procedure for the determination of glycine (Gly) was developed by using a column containing immobilized glutamate dehydrogenase (GDH) on glyoxal agarose beads. Ammonia is produced from the enzymatic reactions between Gly and GDH with NAD(+) in phosphate buffer medium. The indophenol blue method was used for ammonia detection based on the spectrophotometric measurements of blue-colored product absorbing at 640 nm. The calibration graph is linear in the range of 0.1-10 mM of Gly concentrations. The effect of pH, temperature, and time interval was studied to find column stability, and also the interference effects of other amino acids was investigated. The interaction between GDH and glyoxal agarose beads was analyzed by Fourier transform infrared (FTIR) spectroscopy. The morphology of the immobilized and non-immobilized agarose beads were characterized by atomic force microscopy (AFM).

  12. Modification of the Congo red agar method to detect biofilm production by Staphylococcus epidermidis.

    Science.gov (United States)

    Kaiser, Thaís Dias Lemos; Pereira, Eliezer Menezes; Dos Santos, Kátia Regina Netto; Maciel, Ethel Leonor Noia; Schuenck, Ricardo Pinto; Nunes, Ana Paula Ferreira

    2013-03-01

    Staphylococcus epidermidis in immunocompromised patients can cause bacteremia related to the use of catheter due to biofilm production. There are different phenotypic methods to detect biofilm formation. One method is based on culture in brain heart infusion agar (BHIA) containing sucrose and red Congo dye (original Congo red agar). Our group created a new CRA formula and we have confirmed its capacity to detect biofilm production in 210 S. epidermidis strains, including 76 (36.2%) icaAB gene-positive strains. Other parameters were also evaluated. The new CRA formula that gave the best results was BHIA with sucrose (5%), Congo red (0.08%), NaCl (1.5%), glucose (2%), and vancomycin (0.5 mg/mL) (vancomycin-modified CRA-CRAmod). The CRAmod plus vancomycin may be a promising tool and can help to determine the real participation of S. epidermidis in the infectious process. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Electrophoresis of immunoglobulin G. Facilitated migration of minute amounts in agarose

    International Nuclear Information System (INIS)

    Weil, M.L.; Tyrrell, D.L.J.; Norrby, E.

    1978-01-01

    Migration of very small amounts of immunoglobulin (20 ng) is restricted in agarose electrophoresis. Incorporation of a stable protein matrix (rabbit gamma globulin 1 mg/ml) in the agarose permits unrestricted migration so that immunoelectrophoresis of this quantity of radiolabelled antibody is possible. Very small amounts of radiolabelled and non-radiolabelled antibody were subjected to successful crossed immunoelectrophoresis through barriers of antigen under conditions which provide favorable ratios of antibody to antigen. These methods should be useful for studies of antibody eluted from tissue in acquired and autoimmune diseases associated with tissue bound immunoglobulin. (Auth.)

  14. A simple and effective SuperBuffer for DNA agarose electrophoresis.

    Science.gov (United States)

    Zhang, Jun-He; Wang, Fang; Wang, Tian-Yun

    2011-11-01

    In the paper, we describe a unique effective electrophoresis buffer for DNA agarose electrophoresis, called SuperBuffer. Using this buffer, electrophoresis could be performed within 10 min at voltages as high as 25V/cm. In addition, DNA fragments of different lengths could be isolated clearly even at lower agarose gel concentrations and the DNA recovery efficiency was higher than that of the TAE/TBE running buffers. The SuperBuffer still retained its electrophoretic effect even after several uses. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. An Agar-Based Method for Plating Marine Protozoan Parasites of the Genus Perkinsus.

    Science.gov (United States)

    Cold, Emma R; Freyria, Nastasia J; Martínez Martínez, Joaquín; Fernández Robledo, José A

    2016-01-01

    The genus Perkinsus includes protozoan parasites of mollusks responsible for losses in the aquaculture industry and hampering the recovery of natural shellfish beds worldwide, and they are a key taxon for understanding intracellular parasitism adaptations. The ability to propagate the parasite in liquid media, in the absence of the host, has been crucial for improving understanding of its biology; however, alternative techniques to grow the parasite are needed to explore other basic aspects of the Perkinsus spp. biology. We optimized a DME: Ham's F12-5% FBS- containing solid agar medium for plating Perkinsus marinus. This solid medium supported trophozoite propagation both by binary fission and schizogony. Colonies were visible to the naked eye 17 days after plating. We tested the suitability of this method for several applications, including the following: 1) Subcloning P. marinus isolates: single discrete P. marinus colonies were obtained from DME: Ham's F12-5% FBS- 0.75% agar plates, which could be further propagated in liquid medium; 2) Subcloning engineered Perkinsus mediterraneus MOE[MOE]: GFP by streaking cultures on plates; 3) Chemical susceptibility: Infusing the DME: Ham's F12-5% FBS- 0.75% agar plates with triclosan resulted in inhibition of the parasite propagation in a dose-dependent manner. Altogether, our plating method has the potential for becoming a key tool for investigating diverse aspects of Perkinsus spp. biology, developing new molecular tools, and for biotechnological applications.

  16. An Agar-Based Method for Plating Marine Protozoan Parasites of the Genus Perkinsus.

    Directory of Open Access Journals (Sweden)

    Emma R Cold

    Full Text Available The genus Perkinsus includes protozoan parasites of mollusks responsible for losses in the aquaculture industry and hampering the recovery of natural shellfish beds worldwide, and they are a key taxon for understanding intracellular parasitism adaptations. The ability to propagate the parasite in liquid media, in the absence of the host, has been crucial for improving understanding of its biology; however, alternative techniques to grow the parasite are needed to explore other basic aspects of the Perkinsus spp. biology. We optimized a DME: Ham's F12-5% FBS- containing solid agar medium for plating Perkinsus marinus. This solid medium supported trophozoite propagation both by binary fission and schizogony. Colonies were visible to the naked eye 17 days after plating. We tested the suitability of this method for several applications, including the following: 1 Subcloning P. marinus isolates: single discrete P. marinus colonies were obtained from DME: Ham's F12-5% FBS- 0.75% agar plates, which could be further propagated in liquid medium; 2 Subcloning engineered Perkinsus mediterraneus MOE[MOE]: GFP by streaking cultures on plates; 3 Chemical susceptibility: Infusing the DME: Ham's F12-5% FBS- 0.75% agar plates with triclosan resulted in inhibition of the parasite propagation in a dose-dependent manner. Altogether, our plating method has the potential for becoming a key tool for investigating diverse aspects of Perkinsus spp. biology, developing new molecular tools, and for biotechnological applications.

  17. The effect of magnetic nanoparticles on the acoustic properties of tissue-mimicking agar-gel phantoms

    International Nuclear Information System (INIS)

    Józefczak, A.; Kaczmarek, K.; Kubovčíková, M.; Rozynek, Z.; Hornowski, T.

    2017-01-01

    In ultrasonic hyperthermia, ultrasound-induced heating is achieved by the absorption of wave energy and its conversion into heat. The effectiveness of ultrasounds can be improved by using sonosensitisers that greatly attenuate ultrasonic waves and then dissipate the acquired energy in the form of heat. One possible candidate for such a sonosensitiser are superparamagnetic iron oxide nanoparticles. Here, we used magnetic nanoparticles embedded in a tissue-mimicking agar-gel matrix. Such tissue-mimicking phantoms possess acoustic properties similar to those of real tissues, and are used as a tool for performance testing and optimisation of medical ultrasound systems. In this work, we studied the effect of magnetic nanoparticles on the acoustic properties of agar-gel phantoms, including the attenuation of ultrasonic waves. - Highlights: • Ultrasonic insertion technique is used to study acoustic properties of agar-gel phantoms with and without magnetic particles. • The addition of magnetic nanoparticles improves effectiveness of ultrasound heating in agar phantoms. • Acoustics properties of a pure agar-gel phantom are altered by adding nanoparticles.

  18. Fabrication of user-friendly and biomimetic 1,1'-carbonyldiimidazole cross-linked gelatin/agar microfluidic devices.

    Science.gov (United States)

    Jocic, Simonne; Mestres, Gemma; Tenje, Maria

    2017-07-01

    We have developed a straightforward technique for fabricating user-friendly and biomimetic microfluidic devices out of a gelatin/agar gel cross-linked with 1,1'-carbonyldiimidazole. The fabrication procedure requires only inexpensive starting materials such as glass capillaries and wires to mold 3D cylindrical channels into the gel with the possibility of achieving channel diameters of 375μm and 1000μm. We demonstrate that the channel absent of gel injury can retain fluid within its dimensions for at least 7h. We also show that the device material does not autofluoresce nor provide hindrances with fluorescent imaging. A discussion of the chemical linkage identities of cross-linked gelatin/agar is included via ATR-FTIR studies. Crosslinking of the gelatin/agar is further confirmed by the lack of a gel to sol transition at physiological temperature as assessed by DSC measurements. SEM micrographs that demonstrate the 100nm mean pore width of the cross-linked gelatin/agar are provided. This device is considered biomimetic because it represents components present in the natural extracellular matrix such as collagen and proteoglycans in the form of cross-linked gelatin/agar. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. The effect of magnetic nanoparticles on the acoustic properties of tissue-mimicking agar-gel phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Józefczak, A., E-mail: aras@amu.edu.pl [Institute of Acoustics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Kaczmarek, K. [Institute of Acoustics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Kubovčíková, M. [Institute of Experimental Physics, Slovak Academy of Sciences, Košice (Slovakia); Rozynek, Z.; Hornowski, T. [Institute of Acoustics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland)

    2017-06-01

    In ultrasonic hyperthermia, ultrasound-induced heating is achieved by the absorption of wave energy and its conversion into heat. The effectiveness of ultrasounds can be improved by using sonosensitisers that greatly attenuate ultrasonic waves and then dissipate the acquired energy in the form of heat. One possible candidate for such a sonosensitiser are superparamagnetic iron oxide nanoparticles. Here, we used magnetic nanoparticles embedded in a tissue-mimicking agar-gel matrix. Such tissue-mimicking phantoms possess acoustic properties similar to those of real tissues, and are used as a tool for performance testing and optimisation of medical ultrasound systems. In this work, we studied the effect of magnetic nanoparticles on the acoustic properties of agar-gel phantoms, including the attenuation of ultrasonic waves. - Highlights: • Ultrasonic insertion technique is used to study acoustic properties of agar-gel phantoms with and without magnetic particles. • The addition of magnetic nanoparticles improves effectiveness of ultrasound heating in agar phantoms. • Acoustics properties of a pure agar-gel phantom are altered by adding nanoparticles.

  20. Measurement of Ferric Ion Diffusion Coefficient in Fricke-Infused Agarose Gel From MR Image Intensity Changes

    National Research Council Canada - National Science Library

    Tseng, Yin-Jiun

    2001-01-01

    .... Our results showed that for a Fricke-agarose gel contained 1mM ammonium ferrous sulfate, 1% agarose, 1mM sodium chloride and 50mM sulfuric acid, its ferric ion diffusion coefficient is 1.31x10(-2)cm(2)h(-1...

  1. Rapid Isolation and Susceptibility Testing of Leptospira spp. Using a New Solid Medium, LVW Agar

    Science.gov (United States)

    Wuthiekanun, Vanaporn; Amornchai, Premjit; Paris, Daniel H.; Langla, Sayan; Thaipadunpanit, Janjira; Chierakul, Wirongrong; Smythe, Lee D.; White, Nicholas J.; Day, Nicholas P. J.; Peacock, Sharon J.

    2013-01-01

    Pathogenic Leptospira spp., the causative agents of leptospirosis, are slow-growing Gram-negative spirochetes. Isolation of Leptospira from clinical samples and testing of antimicrobial susceptibility are difficult and time-consuming. Here, we describe the development of a new solid medium that facilitates more-rapid growth of Leptospira spp. and the use of this medium to evaluate the Etest's performance in determining antimicrobial MICs to drugs in common use for leptospirosis. The medium was developed by evaluating the effects of numerous factors on the growth rate of Leptospira interrogans strain NR-20157. These included the type of base agar, the concentration of rabbit serum (RS), and the concentration and duration of CO2 incubation during the initial period of culture. The highest growth rate of NR-20157 was achieved using a Noble agar base supplemented with 10% RS (named LVW agar), with an initial incubation at 30°C in 5% CO2 for 2 days prior to continuous culture in air at 30°C. These conditions were used to develop the Etest for three species, L. interrogans (NR-20161), L. kirschnerii (NR-20327), and L. borgpetersenii (NR-20151). The MICs were read on day 7 for all samples. The Etest was then performed on 109 isolates of pathogenic Leptospira spp. The MIC90 values for penicillin G, doxycycline, cefotaxime, ceftriaxone, and chloramphenicol were 0.64 units/ml and 0.19, 0.047, 0.5, and 2 μg/ml, respectively. The use of LVW agar, which enables rapid growth, isolation of single colonies, and simple antimicrobial susceptibility testing for Leptospira spp., provides an opportunity for new areas of fundamental and applied research. PMID:23114772

  2. Corn and potato starch as an agar alternative for Solanum ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-01-04

    Jan 4, 2010 ... Potato single nodes were subcultured onto fresh MS medium gelled with 0, 1 and 2 g/l of agar + 40, 50 or. 60 g/l of commercial corn and potato starch (CS or PS, respectively). After 4 weeks of culture, the pH of medium supplemented with 50 or 60 g/l of CS or 60 g/l of PS was significantly decreased to 3.91 ...

  3. Corn and potato starch as an agar alternative for Solanum ...

    African Journals Online (AJOL)

    Potato single nodes were subcultured onto fresh MS medium gelled with 0, 1 and 2 g/l of agar + 40, 50 or 60 g/l of commercial corn and potato starch (CS or PS, respectively). After 4 weeks of culture, the pH of medium supplemented with 50 or 60 g/l of CS or 60 g/l of PS was significantly decreased to 3.91 - 4.00.

  4. Rapid recovery of DNA from agarose gel slices by coupling electroelution with monolithic SPE.

    Science.gov (United States)

    Yu, Shengbing; Yang, Shuixian; Zhou, Ping; Zhou, Ke; Wang, Jing; Chen, Xiangdong

    2009-06-01

    An amino silica monolithic column prepared by in situ polymerization of tetraethoxysilane and N-(beta-aminoethyl)-gamma-aminopropyltriethoxysilane was firstly applied to recover DNA from agarose gel slices by coupling electroelution with monolithic SPE. DNA was electroeluted from the agarose gel slices onto the amino silica monolithic column. The DNA adsorbed on this monolithic column was then recovered using sodium phosphate solution at pH 10. The whole recovery procedure could be completed within 10 min because the use of amino silica monolithic column accelerated the DNA capture and facilitated the DNA release. Electroelution conditions, such as buffer pH, buffer concentration and applied voltage, were online optimized. The average yield for herring sperm DNA, pBR 322 DNA and lambda DNA recovered from 1.0% w/v agarose gel slices were 55+/-4, 50+/-6 and 42+/-7% (n=3), respectively. The polymerase chain reaction performance of pGM plasmid recovered from agarose gel slices demonstrated that the method could provide high-quality DNA for downstream processes. The combination of electroelution with monolithic SPE allows a rapid, simple and efficient DNA recovery method. This technique is especially useful for applications that need to purify small starting amounts of DNA.

  5. Effects of calcium salts of acidic monomers on mineral induction of phosphoprotein immobilized to agarose beads.

    Science.gov (United States)

    Ito, Shuichi; Iijima, Masahiro; Motai, Fumiko; Mizoguchi, Itaru; Saito, Takashi

    2012-10-01

    The aim of this study is to evaluate the mineralizing potential of acidic monomers and their calcium salts for mineralization, using an in vitro mineral induction model. Phosvitin (PV) was used as a model phosphoprotein in this study. PV was immobilized on agarose beads with divinyl sulfone. Five aliquots of agarose-immobilized PV, acidic monomers, and their calcium salts were incubated in mineralizing solution at various concentrations. The PV beads and acidic monomers were incubated at 37°C. Samples were taken at several time points during the incubation. Then, the agarose beads were analyzed for bound calcium by atomic absorption spectrometry. The mineral formed on the agarose beads was identified as an apatite by microarea X-ray diffraction. Additionally, the specimens were observed using scanning electron microscopy (SEM). Mineral induction time decreased with increasing solution saturation. 4-METCa salt [calcium salt of 4-methacryloxyethyl trimellitate (CMET)] significantly reduced the mineral induction time. Using these data, the interfacial tension for mineral induction of PV and CMET was determined to be 90.1 and 92.7 ergs/cm(2), respectively. The mineral induced in each specimen after incubation for 24 h was identified by its X-ray diffraction pattern as apatite. SEM observation showed that lath-shaped crystals were formed on the surfaces of the CMET. We conclude that CMET could play a role in dentin remineralization. Copyright © 2012 Wiley Periodicals, Inc.

  6. Direct Quantification of Solute Diffusivity in Agarose and Articular Cartilage Using Correlation Spectroscopy.

    Science.gov (United States)

    Shoga, Janty S; Graham, Brian T; Wang, Liyun; Price, Christopher

    2017-10-01

    Articular cartilage is an avascular tissue; diffusive transport is critical for its homeostasis. While numerous techniques have been used to quantify diffusivity within porous, hydrated tissues and tissue engineered constructs, these techniques have suffered from issues regarding invasiveness and spatial resolution. In the present study, we implemented and compared two separate correlation spectroscopy techniques, fluorescence correlation spectroscopy (FCS) and raster image correlation spectroscopy (RICS), for the direct, and minimally-invasive quantification of fluorescent solute diffusion in agarose and articular cartilage. Specifically, we quantified the diffusional properties of fluorescein and Alexa Fluor 488-conjugated dextrans (3k and 10k) in aqueous solutions, agarose gels of varying concentration (i.e. 1, 3, 5%), and in different zones of juvenile bovine articular cartilage explants (i.e. superficial, middle, and deep). In agarose, properties of solute diffusion obtained via FCS and RICS were inversely related to molecule size, gel concentration, and applied strain. In cartilage, the diffusional properties of solutes were similarly dependent upon solute size, cartilage zone, and compressive strain; findings that agree with work utilizing other quantification techniques. In conclusion, this study established the utility of FCS and RICS as simple and minimally invasive techniques for quantifying microscale solute diffusivity within agarose constructs and articular cartilage explants.

  7. Immunoperoxidase staining and radioimmunobinding of human tumor markers separated by direct tissue agarose isoelectric focusing

    International Nuclear Information System (INIS)

    Saravis, C.A.; Cunningham, C.G.; Marasco, P.V.; Cook, R.B.; Zamcheck, N.; FMC Corp., Rockland, ME

    1980-01-01

    The new technique of agarose isoelectric focusing is used to identify, quantitate, and characterize specific tumor markers. After fixation of the isoelectric focusing patterns these are reacted with specific anti-tumor marker antisera, then with second antibody either peroxidase conjugated or radiolabellad (radioiodine). (RB) [de

  8. Simultaneous DNA purification and fractionation in agarose gel on the micro-scale

    NARCIS (Netherlands)

    Gümüscü, B.; van den Berg, Albert; Eijkel, Jan C.T.

    2016-01-01

    We report a new and simple approach for preparative purification and fractionation of sub-10-kbp DNA molecules in a microfluidic device. Agarose gel with 1.2% concentration is used as the separation matrix. A 0.5-10 kbp DNA ladder is fractionated and separated from other ionic species in continuous

  9. Micropatterning of a stretchable conductive polymer using inkjet printing and agarose stamping

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; Hassager, Ole; Larsen, Niels Bent

    2007-01-01

    ,4-ethylenedioxythiophene) (PEDOT). The agarose stamping produced 50 μm wide conducting lines with high spatial fidelity. The deactivation agent was found to cause some degradation of the remaining conducting lines, as revealed by a stronger increase in resistance upon straining compared to the pristine polymer material...

  10. A colorimetric agarose gel for formaldehyde measurement based on nanotechnology involving Tollens reaction.

    Science.gov (United States)

    Zeng, Jing-bin; Fan, Shi-guang; Zhao, Cui-ying; Wang, Qian-ru; Zhou, Ting-yao; Chen, Xi; Yan, Zi-feng; Li, Yan-peng; Xing, Wei; Wang, Xu-dong

    2014-08-04

    Gold nanoparticles (Au NPs) coupled with Tollens reagent were used for measuring formaldehyde. Au@Ag core-shell NPs were formed along with distinct color changes from pink to deep yellow. This colorimetric system was further immobilized into an agarose gel, which was used for monitoring of gaseous formaldehyde.

  11. A simple immunoblotting method after separation of proteins in agarose gel

    DEFF Research Database (Denmark)

    Koch, C; Skjødt, K; Laursen, I

    1985-01-01

    A simple and sensitive method for immunoblotting of proteins after separation in agarose gels is described. It involves transfer of proteins onto nitrocellulose paper simply by diffusion through pressure, a transfer which only takes about 10 min. By this method we have demonstrated the existence ...

  12. Toxicological evaluation of neoagarooligosaccharides prepared by enzymatic hydrolysis of agar.

    Science.gov (United States)

    Hong, Sun Joo; Lee, Je-Hyeon; Kim, Eun Joo; Yang, Hea Jung; Park, Jae-Seon; Hong, Soon-Kwang

    2017-11-01

    Agar, a heterogeneous polymer of galactose, is the main component of the cell wall of marine red algae. It is well established as a safe, non-digestible carbohydrate in Oriental countries. Although neoagarooligosaccharides (NAOs) prepared by the hydrolysis of agar by β-agarase have been reported to exert various biological activities, the safety of these compounds has not been reported to date. For safety evaluation, NAOs containing mainly neoagarotetraose and neoagarohexaose were prepared from agar by enzymatic hydrolysis using β-agarase DagA from Streptomyces coelicolor. Genotoxicity tests such as the bacterial reverse mutation assay, eukaryotic chromosome aberration assay, and in vivo micronucleus assay all indicated that NAOs did not exert any mutational effects. The toxicity of NAOs in rat and beagle dog models was investigated by acute, 14-day, and 91-day repeated oral dose toxicity tests. The results showed that NAO intake of up to 5,000 mg/kg body weight resulted in no significant changes in body weight, food intake, water consumption, hematologic and blood biochemistry parameters, organ weight, or clinical symptoms. Collectively, a no-observed-adverse-effect level of 5,000 mg/kg body weight/day for both male and female rats was established for NAO. These findings support the safety of NAO for possible use in food supplements and pharmaceutical and cosmetic products. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Use of electron beam on aflatoxins degradation in coconut agar

    Energy Technology Data Exchange (ETDEWEB)

    Rogovschi, Vladimir D.; Nunes, Thaise C.F.; Villavicencio, Anna L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: vrogovschi@ipen.br; Aquino, Simone; Goncalez, Edlayne [Instituto Biologico (IB-SP), Sao Paulo, SP (Brazil); Correa, Benedito [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Ciencias Biomedicas

    2009-07-01

    The fungi Aspergillus flavus are capable of producing toxic metabolites, such as aflatoxin, that is one of the most important human carcinogens, according to the 'International Agency for Research on Cancer'. The aim of this study was to compare the effect of electron beam irradiation on degradation of aflatoxin B1 present in laboratorial residues with a dose of 0 kGy and 5.0 kGy. The fungi were cultivated in potato dextrose agar (PDA) for 7 days and transferred to a coconut agar medium, incubated at a temperature of 25 deg C for 14 days to produce the laboratorial wastes (coconut agar) containing aflatoxins. The samples were conditioned in petri dish for radiation treatment of contaminated material and processed in the Electron Accelerator with 0 kGy and 5.0 kGy. Aflatoxin B{sub 1} was extracted with chloroform and separated on a thin layer chromatography plate (TLC) with chloroform: acetone (9:1). All the control and irradiated samples were analyzed in a Shimadzu Densitometer. The detection limit of this methodology is 0.1{mu}g kg{sup -1}. The results indicate that the irradiated samples had a reduction of 75.49 % in the analyzed dose. (author)

  14. Use of electron beam on aflatoxins degradation in coconut agar

    International Nuclear Information System (INIS)

    Rogovschi, Vladimir D.; Nunes, Thaise C.F.; Villavicencio, Anna L.C.H.; Aquino, Simone; Goncalez, Edlayne; Correa, Benedito

    2009-01-01

    The fungi Aspergillus flavus are capable of producing toxic metabolites, such as aflatoxin, that is one of the most important human carcinogens, according to the 'International Agency for Research on Cancer'. The aim of this study was to compare the effect of electron beam irradiation on degradation of aflatoxin B1 present in laboratorial residues with a dose of 0 kGy and 5.0 kGy. The fungi were cultivated in potato dextrose agar (PDA) for 7 days and transferred to a coconut agar medium, incubated at a temperature of 25 deg C for 14 days to produce the laboratorial wastes (coconut agar) containing aflatoxins. The samples were conditioned in petri dish for radiation treatment of contaminated material and processed in the Electron Accelerator with 0 kGy and 5.0 kGy. Aflatoxin B 1 was extracted with chloroform and separated on a thin layer chromatography plate (TLC) with chloroform: acetone (9:1). All the control and irradiated samples were analyzed in a Shimadzu Densitometer. The detection limit of this methodology is 0.1μg kg -1 . The results indicate that the irradiated samples had a reduction of 75.49 % in the analyzed dose. (author)

  15. Molecular analysis of chondrocytes cultured in agarose in response to dynamic compression

    Directory of Open Access Journals (Sweden)

    Mallein-Gerin Frédéric

    2008-09-01

    Full Text Available Abstract Background Articular cartilage is exposed to high mechanical loads under normal physiological conditions and articular chondrocytes regulate the composition of cartilaginous matrix, in response to mechanical signals. However, the intracellular pathways involved in mechanotransduction are still being defined. Using the well-characterized chondrocyte/agarose model system and dynamic compression, we report protocols for preparing and characterizing constructs of murine chondrocytes and agarose, and analyzing the effect of compression on steady-state level of mRNA by RT-PCR, gene transcription by gene reporter assay, and phosphorylation state of signalling molecules by Western-blotting. The mouse model is of particular interest because of the availability of a large choice of bio-molecular tools suitable to study it, as well as genetically modified mice. Results Chondrocytes cultured in agarose for one week were surrounded by a newly synthesized pericellular matrix, as revealed by immunohistochemistry prior to compression experiments. This observation indicates that this model system is suitable to study the role of matrix molecules and trans-membrane receptors in cellular responsiveness to mechanical stress. The chondrocyte/agarose constructs were then submitted to dynamic compression with FX-4000C™ Flexercell® Compression Plus™ System (Flexcell. After clearing proteins off agarose, Western-blotting analysis showed transient activation of Mitogen-activated protein kinases (MAPK in response to dynamic compression. After assessment by capillary electrophoresis of the quality of RNA extracted from agarose, steady-state levels of mRNA expression was measured by real time PCR. We observed an up-regulation of cFos and cJun mRNA levels as a response to compression, in accordance with the mechanosensitive character observed for these two genes in other studies using cartilage explants submitted to compression. To explore further the

  16. Hair sheep blood, citrated or defibrinated, fulfills all requirements of blood agar for diagnostic microbiology laboratory tests.

    Science.gov (United States)

    Yeh, Ellen; Pinsky, Benjamin A; Banaei, Niaz; Baron, Ellen Jo

    2009-07-03

    Blood agar is used for the identification and antibiotic susceptibility testing of many bacterial pathogens. In the developing world, microbiologists use human blood agar because of the high cost and inhospitable conditions for raising wool sheep or horses to supply blood. Many pathogens either fail to grow entirely or exhibit morphologies and hemolytic patterns on human blood agar that confound colony recognition. Furthermore, human blood can be hazardous to handle due to HIV and hepatitis. This study investigated whether blood from hair sheep, a hardy, low-maintenance variety of sheep adapted for hot climates, was suitable for routine clinical microbiology studies. Hair sheep blood obtained by jugular venipuncture was anticoagulated by either manual defibrination or collection in human blood bank bags containing citrate-phosphate-dextrose. Trypticase soy 5% blood agar was made from both forms of hair sheep blood and commercial defibrinated wool sheep blood. Growth characteristics, colony morphologies, and hemolytic patterns of selected human pathogens, including several streptococcal species, were evaluated. Specialized identification tests, including CAMP test, reverse CAMP test, and satellite colony formation with Haemophilus influenzae and Abiotrophia defectiva were also performed. Mueller-Hinton blood agar plates prepared from the three blood types were compared in antibiotic susceptibility tests by disk diffusion and E-test. The results of all studies showed that blood agar prepared from citrated hair sheep blood is suitable for microbiological tests used in routine identification and susceptibility profiling of human pathogens. The validation of citrated hair sheep blood eliminates the labor-intensive and equipment-requiring process of manual defibrination. Use of hair sheep blood, in lieu of human blood currently used by many developing world laboratories and as an alternative to cost-prohibitive commercial sheep blood, offers the opportunity to

  17. Hair sheep blood, citrated or defibrinated, fulfills all requirements of blood agar for diagnostic microbiology laboratory tests.

    Directory of Open Access Journals (Sweden)

    Ellen Yeh

    Full Text Available BACKGROUND: Blood agar is used for the identification and antibiotic susceptibility testing of many bacterial pathogens. In the developing world, microbiologists use human blood agar because of the high cost and inhospitable conditions for raising wool sheep or horses to supply blood. Many pathogens either fail to grow entirely or exhibit morphologies and hemolytic patterns on human blood agar that confound colony recognition. Furthermore, human blood can be hazardous to handle due to HIV and hepatitis. This study investigated whether blood from hair sheep, a hardy, low-maintenance variety of sheep adapted for hot climates, was suitable for routine clinical microbiology studies. METHODS AND FINDINGS: Hair sheep blood obtained by jugular venipuncture was anticoagulated by either manual defibrination or collection in human blood bank bags containing citrate-phosphate-dextrose. Trypticase soy 5% blood agar was made from both forms of hair sheep blood and commercial defibrinated wool sheep blood. Growth characteristics, colony morphologies, and hemolytic patterns of selected human pathogens, including several streptococcal species, were evaluated. Specialized identification tests, including CAMP test, reverse CAMP test, and satellite colony formation with Haemophilus influenzae and Abiotrophia defectiva were also performed. Mueller-Hinton blood agar plates prepared from the three blood types were compared in antibiotic susceptibility tests by disk diffusion and E-test. CONCLUSIONS: The results of all studies showed that blood agar prepared from citrated hair sheep blood is suitable for microbiological tests used in routine identification and susceptibility profiling of human pathogens. The validation of citrated hair sheep blood eliminates the labor-intensive and equipment-requiring process of manual defibrination. Use of hair sheep blood, in lieu of human blood currently used by many developing world laboratories and as an alternative to cost

  18. Potential of Agarose/Silk Fibroin Blended Hydrogel for in Vitro Cartilage Tissue Engineering.

    Science.gov (United States)

    Singh, Yogendra Pratap; Bhardwaj, Nandana; Mandal, Biman B

    2016-08-24

    An osteoarthritis pandemic has accelerated exploration of various biomaterials for cartilage reconstruction with a special emphasis on silk fibroin from mulberry (Bombyx mori) and non-mulberry (Antheraea assamensis) silk worms. Retention of positive attributes of the agarose standard and nullification of its negatives are central to the current agarose/silk fibroin hydrogel design. In this study, hydrogels of mulberry and non-mulberry silk fibroin blended with agarose were fabricated and evaluated in vitro for two weeks for cartilaginous tissue formation. The fabricated hydrogels were physicochemically characterized and analyzed for cell viability, proliferation, and extra cellular matrix deposition. The amalgamation of silk fibroin with agarose impacted the pore size, as illustrated by field emission scanning electron microscopy studies, swelling behavior, and in vitro degradation of the hydrogels. Fourier transform infrared spectroscopy results indicated the blend formation and confirmed the presence of both components in the fabricated hydrogels. Rheological studies demonstrated enhanced elasticity of blended hydrogels with G' > G″. Biochemical analysis revealed significantly higher levels of sulfated glycosaminoglycans (sGAGs) and collagen (p ≤ 0.01) in blended hydrogels. More specifically, the non-mulberry silk fibroin blend showed sGAG and collagen content (∼1.5-fold) higher than that of the mulberry blend (p ≤ 0.05). Histological and immunohistochemical analyses further validated the enhanced deposition of sGAG and collagen, indicating maintenance of chondrogenic phenotype within constructs after two weeks of culture. Real-time PCR analysis further confirmed up-regulation of cartilage-specific aggrecan, sox-9 (∼1.5-fold) and collagen type II (∼2-fold) marker genes (p ≤ 0.01) in blended hydrogels. The hydrogels demonstrated immunocompatibility, which was evidenced by minimal in vitro secretion of tumor necrosis factor-α (TNF-α) by murine

  19. Evaluatie van de membraanfiltratiemethode op mCP-agar voor bepaling van sporen van Clostridium perfringens in water

    NARCIS (Netherlands)

    Schets FM; Medema GJ; LWL

    1995-01-01

    Current Dutch and European drinking water standards include criteria for spores of sulphite reducing clostridia. This has some inherent disadvantages. The reproducibility of the enumeration method for spores of sulphite reducing clostridia (SSRC) in Sulphite Cycloserine Agar (SCA) is poor. Some

  20. Recovery of Lactobacillus bulgaricus and Streptococcus thermophilus on Nine Commonly Used Agar Media1

    Science.gov (United States)

    Moon, Nancy J.; Hamann, A. C.; Reinbold, G. W.

    1974-01-01

    Of the nine media tested, Eugon, Elliker's lactic agar, pH 6.8, and modified tryptic soy broth agars showed superior recovery of Lactobacillus bulgaricus and Streptococcus thermophilus strains. PMID:16350006

  1. Physicochemical, morphological and therapeutic evaluation of agarose hydrogel particles as a reservoir for basic fibroblast growth factor.

    Science.gov (United States)

    Moribe, Kunikazu; Nomizu, Natsuko; Izukura, Shunsuke; Yamamoto, Keiji; Tozuka, Yuichi; Sakurai, Manabu; Ishida, Atsushi; Nishida, Hirofumi; Miyazaki, Masaru

    2008-01-01

    Micron-sized agarose hydrogel particles were prepared using an emulsification/gelation method as a controlled release reservoir for basic fibroblast growth factor (bFGF). Mean particle size of agarose hydrogel particles decreased with an increase in stirring speed and also with an increasing temperature of the oil phase, as measured before cooling. Morphologies of agarose particles before and after dispersing into water were investigated by scanning electron microscopy (SEM) and cryogenic SEM, respectively. Freeze-dried agarose particles were spherical with rough surface. Porous polymer matrix structure was observed in the hydrogel particles by cryo-SEM. More than 99% of bFGF was encapsulated and the release from the agarose hydrogel particles was less than 3% during the incubation in phosphate buffered saline. bFGF molecules were not only adsorbed on the particle surface but also permeated and retained within the matrix. The therapeutic efficacy of bFGF retained in agarose hydrogel particles was significantly higher than that dissolved in saline. Agarose hydrogel particle seems to be a potential candidate for a bFGF reservoir.

  2. Preparative two-dimensional gel electrophoresis with agarose gels in the first dimension for high molecular mass proteins.

    Science.gov (United States)

    Oh-Ishi, M; Satoh, M; Maeda, T

    2000-05-01

    A two-dimensional gel electrophoresis (2-DE) method that uses an agarose isoelectric focusing (IEF) gel in the first dimension (agarose 2-DE) was compared with an immobilized pH gradient 2-DE method (IPG-Dalt). The former method was shown to produce significant improvements in the 2-D electrophoretic separation of high molecular mass proteins larger than 150 kDa, up to 500 kDa, and to have a higher loading capacity, as much as 1.5 mg proteins in total for micropreparative runs. The extraction medium found best in this study for agarose 2-DE of mammal tissues was 6 M urea, 1 M thiourea, 0.5% 2-mercaptoethanol, protease inhibitor cocktail (Complete Mini EDTA-free), 1% Triton X-100 and 3% 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS). Trichloroacetic acid (TCA) treatment of the agarose gel after IEF is to be carefully weighed beforehand, because some high molecular mass proteins were less likely to enter the second-dimensional polyacrylamide gel after TCA fixation, and proteins such as mouse skeletal muscle actin gave pseudospots in the agarose 2-DE patterns without TCA fixation. As a good compromise we suggest fixation of proteins in the agarose gel with TCA for one hour or less. The first-dimensional agarose IEF gel containing Pharmalyte as a carrier ampholyte was 180 mm in length and 2.5-4.8 mm in diameter. The gel diameter was shown to determine the loading capacity of the agarose 2-DE, and 1.5 mg liver proteins in total were successfully separated by the use of a 4.8 mm diameter agarose gel.

  3. Improved toluidine blue-DNA agar for detection of DNA hydrolysis by campylobacters.

    OpenAIRE

    Lior, H; Patel, A

    1987-01-01

    Our improved toluidine blue-DNA agar was compared with methyl green DNase test agar for the detection of DNA hydrolysis by campylobacters. The toluidine blue-DNA agar gave clear-cut positive and negative reactions with campylobacter strains belonging to several species.

  4. Development of an eco-friendly agar extraction technique from the red seaweed Gracilaria lemaneiformis.

    Science.gov (United States)

    Li, Haiyan; Yu, Xingju; Jin, Yan; Zhang, Wei; Liu, Yuanling

    2008-05-01

    The red seaweed, Gracilaria lemaneiformis growing as an aquaculture bioremediator along the coasts of Liaodong Peninsula, China, was investigated for the agar production. An eco-friendly method called agar photobleaching extraction process was developed for the benefit of workers' health and safety of the environment. The native agar (NA), alkali-modified agar (AA), chemical-bleached agar (CA) and photobleached agar (PA), which were extracted using different processes, were evaluated for their physical and chemical properties. The PA showed most desirable performances in terms of gel strength, gelling temperature, sulfate content and 3,6-anhydro-l-galactose content. Among the different processed agars, PA gel strength was 1913 g/cm2, the highest among the different processed agars, which increased 8.6% on the basis of the AA. Further we applied this new technique to extract agars from Gracilaria asiatica, and similar results were obtained with that of G. lemaneiformis. This indicates that the agar photobleaching extraction process is a feasible method for Gracilaria species and has a potential application. During the whole agar photobleaching extraction process the pigment content of G. lemaneiformis declined gradually and the TOC concentration in photobleaching solution increased along with the increase in the irradiation time. The mechanism of agar photobleaching could be elucidated by the photolysis theory.

  5. Differential recovery of Streptococcus mutans from various mitis-salivarius agar preparations.

    Science.gov (United States)

    Liljemark, W F; Okrent, D H; Bloomquist, C G

    1976-07-01

    Recoveries of Streptococcus mutans from human dental plaque were lower when plated on mitis-salivarius agar obtained from Baltimore Biological Laboratories as compared with mitis-salivarius agar obtained from Difco Laboratories. However, no difference in recoveries of established laboratory strains of S. mutans was observed between these two agar preparations.

  6. Electrospinning of agar/PVA aqueous solutions and its relation with rheological properties

    Science.gov (United States)

    In this work, we report the successful fabrication of agar-based nanofibers by an electrospinning technique using water as the solvent media. A tubeless spinneret was attached inside the electrospinning chamber, operated at 50 deg C, to avoid agar gelation. Pure agar solution 1% (w/w) showed inadequ...

  7. [Agar gel diffusion precipitation and immunoelectrophoresis of the Aujeszky virus].

    Science.gov (United States)

    Arnaudov, Kh

    1976-01-01

    Two virulent and two vaccinal virus strains are dealt with. The study has been carried out by means of the diffusion precipitation reaction in agar gel and the immunoelectrophoresis technique using hyperimmune sera obtained from cocks as well as concentrated and purified antigens. It has been demonstrated that the virulent and the vaccinal (latent) strains of Aujeszky's disease virus cannot be differentiated serologically. The complex of antibodies induced by the virulent and the latent strains has proved to contain absolutely identical products. On the basis of the results obtained it is suggested to find some other means (markers) to differentiate the virulent from the latent strains of the virus.

  8. Comparison of lithium chloride-phenylethanol-moxalactam and modified Vogel Johnson agars for detection of Listeria spp. in retail-level meats, poultry, and seafood.

    Science.gov (United States)

    Buchanan, R L; Stahl, H G; Bencivengo, M M; Del Corral, F

    1989-03-01

    The effectiveness of Modified Vogel Johnson agar and lithium chloride-phenylethanol-moxalactam agar for detection of Listeria spp. in foods was compared by using the media to analyze retail-level meat, poultry, and seafood both by direct plating and in conjunction with a three-tube most-probable-number enrichment. The most-probable-number protocol detected Listeria species, including Listeria monocytogenes, in a substantial portion of the fresh meat and seafood samples. In most instances the Listeria levels were less than 2 CFU/g, which precluded detection by direct plating. Modified Vogel Johnson agar performed as well as did lithium chloride-phenylethanol-moxalactam agar and was considerably easier to use because of its ability to differentiate Listeria spp. from other microorganisms.

  9. Structural aspects of magnetic fluid stabilization in aqueous agarose solutions

    Energy Technology Data Exchange (ETDEWEB)

    Nagornyi, A.V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Taras Shevchenko National University of Kyiv, Kyiv (Ukraine); Petrenko, V.I., E-mail: vip@nf.jinr.ru [Joint Institute for Nuclear Research, Dubna (Russian Federation); Taras Shevchenko National University of Kyiv, Kyiv (Ukraine); Avdeev, M.V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Yelenich, O.V.; Solopan, S.O.; Belous, A.G. [V.I.Vernadsky Institute of General and Inorganic Chemistry of the Ukrainian NAS, Kyiv (Ukraine); Gruzinov, A.Yu. [National Research Centre “Kurchatov Institute”, Moscow (Russian Federation); Ivankov, O.I. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Institute for Safety Problems of Nuclear Power Plants of the Ukrainian NAS, Kyiv (Ukraine); Bulavin, L.A. [Taras Shevchenko National University of Kyiv, Kyiv (Ukraine); Institute for Safety Problems of Nuclear Power Plants of the Ukrainian NAS, Kyiv (Ukraine)

    2017-06-01

    Structure characterization of magnetic fluids (MFs) synthesized by three different methods in aqueous solutions of agarose was done by means of small-angle neutron (SANS) and synchrotron X-ray scattering (SAXS). The differences in the complex aggregation observed in the studied magnetic fluids were related to different stabilizing procedures of the three kinds of MFs. The results of the analysis of the scattering (mean size of single polydisperse magnetic particles, fractal dimensions of the aggregates) are consistent with the data of transmission electron microscopy (TEM). - Highlights: • MFs synthesized by three different methods in agarose solution were studied. • all MFs are agglomerated colloidal systems whose structures are nevertheless stable in time. • differences in the complex aggregation were observed in the studied magnetic fluids. • results of the SAXS and SANS analysis are consistent with TEM data.

  10. Preparation and structural characterization of O-acetyl agarose with low degree of substitution

    Directory of Open Access Journals (Sweden)

    Rosangela B. Garcia

    2000-09-01

    Full Text Available Among the biodegradable polymers, the polysaccharides have been found to be promising carriers for bioactive molecules. From a general standpoint, they present several reactive groups, such as hydroxyl, carboxyl and amine, that can be modified in a number of ways, giving rise to suitable devices for controlled release. In this paper, agarose was submitted to O-acetylation reactions under heterogeneous conditions, using acetic anhydride and pyridine, aiming to observe the effect of acetyl groups on the agarose properties. The products were characterized by Infrared and ¹H NMR spectroscopies. In the range of average acetylation degrees (DA 0.07-0.48, the polymers presented partial solubility in boiling water and in common organic solvents. The ¹H NMR spectra presented evidences of non-homogeneous acetyl group distribution along the chains, as concluded from the solubility of only one of the fractions with DA<0.09, in boiling water .

  11. Mechanics and transport phenomena in agarose-based hydrogels studied by compression-relaxation tests.

    Science.gov (United States)

    Caccavo, Diego; Cascone, Sara; Poto, Serena; Lamberti, Gaetano; Barba, Anna Angela

    2017-07-01

    Hydrogels are widespread materials, used in several frontier fields, due to their peculiar behavior: they couple solvent mass transport to system mechanics, exhibiting viscoelastic and poroelastic characteristics. The full understanding of this behavior is crucial to correctly design such complex systems. In this study agarose gels has been investigated through experimental stress-relaxation tests and with the aid of a 3D poroviscoelastic model. At the investigated experimental conditions, the agarose gels samples show a prevalent viscoelastic behavior, revealing limited water transport and an increase of the stiffness as well as of the relaxation time along with the polymer concentration. The model parameters, derived from the fitting of some experimental data, have been generalized and used to purely predict the behavior of another set of gels. The stress-relaxation tests coupled with mathematical modeling demonstrated to be a powerful tool to study hydrogels' behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Agarose gel shift assay reveals that calreticulin favors substrates with a quaternary structure in solution

    DEFF Research Database (Denmark)

    Boelt, Sanne Grundvad; Houen, Gunnar; Højrup, Peter

    2015-01-01

    Here we present an agarose gel shift assay that, in contrast to other electrophoresis approaches, is loaded in the center of the gel. This allows proteins to migrate in either direction according to their isoelectric points. Therefore, the presented assay enables a direct visualization, separation...... structure. It is also demonstrated that the agarose gel shift assay is useful in the study of other protein interactions and can be used as an alternative method to native polyacrylamide gel electrophoresis....... measure of interactions. Therefore, no interaction studies between calreticulin and substrates in solution have been investigated previously. The results presented here indicate that calreticulin has a preference for substrates with a quaternary structure and primarily β-sheets in their secondary...

  13. Improved blastocyst development of single cow OPU-derived presumptive zygotes by group culture with agarose-embedded helper embryos

    Directory of Open Access Journals (Sweden)

    Dey Shukla

    2011-08-01

    Full Text Available Abstract Background The in vitro culture of presumed zygotes derived from single cow ovum pick-up (OPU is important for the production of quality blastocysts maintaining pedigree. The aim of the present study was to evaluate the agar chip-embedded helper embryo coculture system for single cow OPU-derived zygotes by assessing embryo quality. Methods Cumulus oocyte complexes (COCs were collected from Hanwoo cows with high genetic merit twice a week using the ultra-sound guided OPU technique and from slaughterhouse ovaries. The Hanwoo cow COCs and slaughterhouse ovaries were matured in vitro, fertilized in vitro with thawed Hanwoo sperm and cultured for 24 h. The presumed zygotes were subsequently placed in three different culture systems: (1 control OPU (controlOPU with single cow OPU-derived presumed zygotes (2~8; (2 agar chip-embedded slaughterhouse helper embryo coculture (agarOPU with ten presumed zygotes including all presumed zygotes from a cow (2~8 and the rest from agar chip-embedded slaughterhouse presumed zygotes (8~2; and (3 slaughterhouse in vitro embryo production (sIVP with ten slaughterhouse ovary-derived presumed zygotes, each in 50 μL droplets. Day 8 blastocysts were assayed for apoptosis and gene expression using real time PCR. Results The coculture system promoted higher blastocyst development in OPU zygotes compared to control OPU zygotes cultured alone (35.2 vs. 13.9%; P CD9, 0.4-fold; AKRAB1, 0.3-fold and in cocultured zygotes (CD9, 0.3-fold; AKRAB1, 0.3-fold compared to sIVP blastocysts (1.0-fold. Moreover, genes involved in implantation and/or normal calf delivery were up-regulated (P PGSH2, 5.0-fold; TXN, 4.3-fold; PLAU, 1.7-fold and cocultured zygotes (PGSH2, 14.5-fold; TXN, 3.2-fold; PLAU, 6.8-fold compared to sIVP (1.0-fold blastocysts. However, the expression of PLAC8, TGF-β1, ODC1, ATP5A1 and CASP3 did not differ between the three culture groups. Conclusions Results show that the agar chip-embedded helper embryo

  14. Enumeration of heterotrophic bacteria in water for dialysis: Comparison of the efficiency of reasoner’2 agar and plate count agar

    Science.gov (United States)

    Bugno, Adriana; Almodóvar, Adriana Aparecida Buzzo; Pereira, Tatiana Caldas

    2010-01-01

    Due to the fact the incubation conditions may influence the microbiological evaluation of water for dialysis, the objective of the present study was the comparison of the efficiency of R2A and PCA media in the enumeration of heterotrophic bacteria in 193 samples of water collected in dialysis clinics from 12 cities in São Paulo, between October and December 2007. Results showed counts significantly greater in R2A, suggesting that enumeration should be carried out in R2A, suggesting that enumeration should be carried out in R2A agar associated with longer incubation times, because of the greater sensitivity. PMID:24031456

  15. Enumeration of heterotrophic bacteria in water for dialysis: comparison of the efficiency of Reasoner'2 agar and plate count agar

    Directory of Open Access Journals (Sweden)

    Adriana Bugno

    2010-03-01

    Full Text Available Due to the fact the incubation conditions may influence the microbiological evaluation of water for dialysis, the objective of the present study was the comparison of the efficiency of R2A and PCA media in the enumeration of heterotrophic bacteria in 193 samples of water collected in dialysis clinics from 12 cities in São Paulo, between October and December 2007. Results showed counts significantly greater in R2A, suggesting that enumeration should be carried out in R2A, suggesting that enumeration should be carried out in R2A agar associated with longer incubation times, because of the greater sensitivity.

  16. Confirmation of soybean plastid rRNAs by formaldehyde denaturing agarose gel electrophoresis.

    Science.gov (United States)

    Zhu, Y Q; Zheng, Y; Chen, H B; Huang, L Q

    2014-10-27

    Owing to their prokaryotic origin, plastid rRNAs are mainly 23s/16s/5s rRNAs. We present a novel plant RNA isolation method in this paper. Also, not only the eukaryotic 28s (26s, 25s)/18s rRNAs but the prokaryotic 26s/23s rRNAs as well were demonstrated in a single sample for the first time by formaldehyde denaturing agarose gel electrophoresis.

  17. Screening for Amyloid Aggregation by Semi-Denaturing Detergent-Agarose Gel Electrophoresis

    OpenAIRE

    Halfmann, Randal; Lindquist, Susan

    2008-01-01

    Amyloid aggregation is associated with numerous protein misfolding pathologies and underlies the infectious properties of prions, which are conformationally self-templating proteins that are thought to have beneficial roles in lower organisms. Amyloids have been notoriously difficult to study due to their insolubility and structural heterogeneity. However, resolution of amyloid polymers based on size and detergent insolubility has been made possible by Semi-Denaturing Detergent-Agarose Gel El...

  18. Agarose cell block technique as a complementary method in the ...

    African Journals Online (AJOL)

    However, additional stains including periodic acid-Schiff (PAS) were positive for fungal hyphae, which rendered a diagnosis of fungal osteomyelitis due to Aspergillus spp. This case report illustrates an uncommon cause of osteomyelitis for breed that was diagnosed by an underused method in veterinary medicine.

  19. The Influence of Conditioning Agent on Phosphate Diffusion Coefficient through Polyacrylamide and Agarose Gel

    Directory of Open Access Journals (Sweden)

    Layta Dinira

    2013-03-01

    Full Text Available Excess phosphate in natural water can cause algae grow rapidly, to the extent causing many fish deaths that led to the extinction of certain species. Therefore, an analysis or periodic observations of phosphate levels in the water is needed. The commonly used method is diffusive gradient in thin films (DGT technique. The DGT technique is based on the ability of analyte to diffuse through a gel, which have a value named diffusion coefficient. This research was conducted in order to study the effect of different storage solution to the phosphate diffusion coefficient through polyacrylamide and agarose gels. Initial research performed with making the polyacrylamide and agarose gels. To observe the effect of different storage solutions, the gels partly stored in distilled water gel while the others are stored in a NaCl solution of 0.01 M. Phosphate diffusion coefficient was determined using Fick's Law after analyze the phosphate concentration using UV-Visible spectrophotometer. The results showed that phosphate diffusion coefficient was highest when polyacrylamide and agarose gels stored in NaCl solution of 0.01 M.

  20. Cryopreservation of very low numbers of spermatozoa from male patients undergoing infertility treatment using agarose capsules.

    Science.gov (United States)

    Hatakeyama, Shota; Tokuoka, Susumu; Abe, Hiroyuki; Araki, Yasuyuki; Araki, Yasuhisa

    2017-07-01

    This study tried to cryopreserve low numbers of spermatozoa from men undergoing infertility treatments by inserting into agarose capsules. The capsules were transferred into a drop of cryoprotectant solution and injected 3-4 motile spermatozoa that were selected by the swim-up method by conventional intracytoplasmic sperm injection. These capsules were put on a Cryotop ® and frozen in liquid nitrogen vapor, and then submerged into liquid nitrogen and subsequently thawed and recovered. The motile spermatozoa in the capsules were counted. Eventually, we cryopreserved 2142 motile spermatozoa in 702 agarose capsules from 26 male patients and 1356 (63%) spermatozoa maintained their motility after thawing. The spermatozoa motility rates after thawing (MRAT) ranged from 20.0% (5/25) to 95.1% (58/61) among patients. The median MRAT was 68.3% (interquartile range 46.1-75.7). The total number of motile spermatozoa collected by swim-up method strongly correlated with MRAT (r = 0.746). It was possible to cryopreserve spermatozoa from male patients undergoing infertility treatment using agarose capsules. However, there were wide differences in MRAT among patients. It seems the spermatozoa from semen where there were many motile spermatozoa may have higher freezing resistance. Further studies using this method in cryptozoospermic semen, testicular and epididymal spermatozoa are required.

  1. Response surface methodology-based optimisation of agarose gel electrophoresis for screening and electropherotyping of rotavirus.

    Science.gov (United States)

    Mishra, Vikas; Nag, Vijaya Lakshmi; Tandon, Ritu; Awasthi, Shally

    2010-04-01

    Management of rotavirus diarrhoea cases and prevention of nosocomial infection require rapid diagnostic method at the patient care level. Diagnostic tests currently available are not routinely used due to economic or sensitivity/specificity constraints. Agarose-based sieving media and running conditions were modulated by using central composite design and response surface methodology for screening and electropherotyping of rotaviruses. The electrophoretic resolution of rotavirus genome was calculated from input parameters characterising the gel matrix structure and running conditions. Resolution of rotavirus genome was calculated by densitometric analysis of the gel. The parameters at critical values were able to resolve 11 segmented rotavirus genome. Better resolution and electropherotypic variation in 11 segmented double-stranded RNA genome of rotavirus was detected at 1.96% (w/v) agarose concentration, 0.073 mol l(-1) ionic strength of Tris base-boric acid-ethylenediamine tetraacetic acid buffer (1.4x) and 4.31 h of electrophoresis at 4.6 V cm(-1) electric field strength. Modified agarose gel electrophoresis can replace other methods as a simplified alternative for routine detection of rotavirus where it is not in practice.

  2. Capillary blotting of glycosaminoglycans on nitrocellulose membranes after agarose-gel electrophoresis separation.

    Science.gov (United States)

    Volpi, Nicola; Maccari, Francesca

    2009-01-01

    A method for the blotting and immobilizing of several nonsulfated and sulfated complex polysaccharides on membranes made hydrophilic and positively charged by cationic detergent after their separation by conventional agarose gel electrophoresis is illustrated. This new approach to the study of glycosaminoglycans (GAGs) utilizes the capacity of agarose gel electrophoresis to separate single species of polysaccharides from mixtures and the membrane technology for further preparative and analytical uses.Nitrocellulose membranes are derivatized with the cationic detergent cetylpyridinium chloride and mixtures of GAGs are capillary blotted after their separation in agarose gel electrophoresis. Single purified species of variously sulfated polysaccharides are transferred on derivatized membranes with an efficiency of 100% and stained with alcian blue (irreversible staining) and toluidine blue (reversible staining). This enables a lower amount limit of detection of 0.1 microg. Nonsulfated polyanions, for example hyaluronic acid, may also be transferred to membranes with a limit of detection of approximately 0.1-0.5 microg after irreversible or reversible staining. The membranes may be stained with reversible staining and the same lanes are used for immunological detection or other applications.

  3. Simple and practical staining of DNA with GelRed in agarose gel electrophoresis.

    Science.gov (United States)

    Huang, Qing; Baum, Larry; Fu, Wei-Ling

    2010-01-01

    Although SYBR Gold or SYBR Green I have been used in the loading buffer as a DNA stain safer than ethidium bromide for agarose gel electrophoresis, electrophoretic mobility of DNA is altered and thus DNA fragment size cannot be accurately determined. A method using GelRed in the loading buffer was developed to stain DNA fragments in agarose gel electrophoresis. Among various concentrations of GelRed, SYBR Gold, or SYBR Green I tested in the loading buffer, only the highest tested concentration of GelRed, i.e., 100x GelRed, did not change band mobility. Evaluations using various sizes of PCR products at different concentrations further confirmed that 100x GelRed could be used to accurately determine DNA fragment size. The reagent can be stored at 4 degrees C for at least 1 year without a decrease in staining sensitivity. The 100x GelRed is a sensitive and safe alternative to ethidium bromide and better than either SYBR Gold or SYBR Green I for size determination in agarose gel electrophoresis. Our laboratory now uses the GelRed method routinely with great consistency and success.

  4. Application of agar liquid-gel transition in cultivation and harvesting of microalgae for biodiesel production.

    Science.gov (United States)

    Kumar, Vinod; Nanda, Manisha; Verma, Monu

    2017-11-01

    In order to increase microalgal biomass productivity efficient cultivation and harvesting methods are needed against the available traditional methods. The present study focuses on the same by harvesting microalgae using agar gel. Agar medium containing bold's basal medium (BBM) undergoes a thermoreversible gel transition. As compared to the traditional protocols, this gel is used to cultivate microalgae without even affecting the total productivity. To develop the gel for microalgae cultivation, agar was boiled in BBM. Then the agar was cooled to 35°C and microalgae culture was added to it. After seeding the microalgae the temperature of the agar was further decreased by 10°C to induce gelation. Instead of isolated cells microalgae were grown in clusters within the agar gel. Microalgal clusters gravimetrically settle at the bottom within 2h. In this method agar can be reused. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Campylobacter in broiler slaughter samples assessed by direct count on mCCDA and Campy-Cefex agar.

    Science.gov (United States)

    Gonsalves, Camila Cristina; Borsoi, Anderlise; Perdoncini, Gustavo; Rodrigues, Laura Beatriz; do Nascimento, Vladimir Pinheiro

    2016-01-01

    Campylobacter spp. cause foodborne illnesses in humans primarily through the consumption of contaminated chicken. The aim of this study was to evaluate the United States Department of Agriculture's (USDA) recommended methodology, protocol MLG 41.02, for the isolation, identification and direct plate counting of Campylobacter jejuni and C. coli samples from the broiler slaughtering process. A plating method using both mCCDA and Campy-Cefex agars is recommended to recover Campylobacter cells. It is also possible to use this method in different matrices (cloacal swabs and water samples). Cloacal swabs, samples from pre-chiller and post-chiller carcasses and samples of pre-chiller, chiller and direct supply water were collected each week for four weeks from the same flock at a slaughterhouse located in an abattoir in southern Brazil. Samples were analyzed to directly count Campylobacter spp., and the results showed a high frequency of Campylobacter spp. on Campy-Cefex agar. For the isolated species, 72% were identified as Campylobacter jejuni and 38% as Campylobacter coli. It was possible to count Campylobacter jejuni and Campylobacter coli from different samples, including the water supply samples, using the two-agar method. These results suggest that slaughterhouses can use direct counting methods with both agars and different matrices as a monitoring tool to assess the presence of Campylobacter bacteria in their products. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  6. Campylobacter in broiler slaughter samples assessed by direct count on mCCDA and Campy-Cefex agar

    Directory of Open Access Journals (Sweden)

    Camila Cristina Gonsalves

    Full Text Available ABSTRACT Campylobacter spp. cause foodborne illnesses in humans primarily through the consumption of contaminated chicken. The aim of this study was to evaluate the United States Department of Agriculture's (USDA recommended methodology, protocol MLG 41.02, for the isolation, identification and direct plate counting of Campylobacter jejuni and C. coli samples from the broiler slaughtering process. A plating method using both mCCDA and Campy-Cefex agars is recommended to recover Campylobacter cells. It is also possible to use this method in different matrices (cloacal swabs and water samples. Cloacal swabs, samples from pre-chiller and post-chiller carcasses and samples of pre-chiller, chiller and direct supply water were collected each week for four weeks from the same flock at a slaughterhouse located in an abattoir in southern Brazil. Samples were analyzed to directly count Campylobacter spp., and the results showed a high frequency of Campylobacter spp. on Campy-Cefex agar. For the isolated species, 72% were identified as Campylobacter jejuni and 38% as Campylobacter coli. It was possible to count Campylobacter jejuni and Campylobacter coli from different samples, including the water supply samples, using the two-agar method. These results suggest that slaughterhouses can use direct counting methods with both agars and different matrices as a monitoring tool to assess the presence of Campylobacter bacteria in their products.

  7. Comparison of Schaedler agar and trypticase soy-yeast extract agar for the cultivation of anaerobic bacteria.

    Science.gov (United States)

    Starr, S E; Killgore, G E; Dowell, V R

    1971-10-01

    Schaedler agar (SA) and Trypticase soy-yeast extract agar (TSYEA), both supplemented with rabbit blood (5%, v/v) and menadione (0.5 mg/liter), were compared with respect to quantitative recovery, quality of growth, and rapidity of growth of selected anaerobic bacteria. The media were stored for 2 to 4 days prior to use in an anaerobic glove box, where all subsequent bacteriological procedures were performed. After 24 hr of incubation, colonies of Clostridium cadaveris (C. capitovale), C. haemolyticum, C. novyi A, and C. perfringens were larger on SA than on TSYEA, and the appearance of C. novyi B colonies on SA at 24 hr antedated their appearance on TSYEA. Quantitative recovery of C. novyi B was improved on SA; recovery of the other clostridia tested was comparable on the two media (inconclusive results were obtained with C. novyi A). Rough colonial types of some of the clostridia emerged on SA. No appreciable differences in results with the two media were noted for Bacteroides fragilis, B. melaninogenicus, or Fusobacterium fusiforme.

  8. ON STAUDE' S NEW GENERIC NAMES FOR AGARICS

    Directory of Open Access Journals (Sweden)

    M. A. DONK

    2015-11-01

    Full Text Available The author concludes that the generic names for agarics first introduced by Staude (1857 have been validly published.When I drew attention to Staude's forgotten "Die Schwamme Mittel-deutschlands" (1857, I felt obliged to conclude that the new generic names for agarics appearing in that work were validly published (Donk, 1949: 319-320, and I still am fully convinced that this conclusion must be upheld. Rogers (1950: 22 submitted that Staude, although referring to Collybia and other genera as G [attungen], did not definitely accept them as genera, since he continued to refer species under them to Agaricus, thereby implying that they were only subgenera or sections; and that Staude, therefore, dit not validly publish these generic names. Rogers's conclusion is untenable for several reasons. If his argumentbecame generally accepted, quite a lot of generic names might be murdered by it: the number of generic names established without simultaneously published new combinations with the new generic name, like those without any mention of species, is considerable. Such an attitude would not only be undesirable from a practical point of view, but would also disregard the declared object of the Code to promote stability of nomenclature. The Code has deliberately and carefully avoided the stipulation that a new generic name requires simultaneously published new combinations; it has even refused to rule that new generic names ought to be associated with binomials, as was stipulated by the former American code! Certainlythis was not done solely to accomodate such special cases as, for example, Tournefortian generic names published after 1753 as an overflow from the pre-binomial period: the decision was for general application. Staude emphatically marked the names in question as generic ones; not only in the introductory pages, but also throughout his more detailed treatment of the agarics he preceded these generic names with "G[attung]" and added generic

  9. Self-spreading method for forming lipid bilayer on a patterned agarose gel: Toward precise lipid bilayer patterning.

    Science.gov (United States)

    Shimba, Kenta; Shoji, Kazuma; Miyamoto, Yoshitaka; Yagi, Tohru

    2017-07-01

    Forming artificial cell membranes is a suitable strategy for studying drug responses of membrane proteins. In order to form lipid bilayer with both mechanical stability and membrane protein functions, hydrogel supported bilayer has attracted attentions. Combinational use of self-extraction method for lipid bilayer formation and agarose gel patterning should realize hydrogel-supported bilayer with any shape and large area. In this study, we aimed to form a lipid bilayer on a patterned agarose gel and to characterize the membrane. First, lipid mixture was attached on an agarose gel, and lipid layers spread on the gel surface. With fluorescent observation, it is suggested that thin lipid layer was formed on the agarose gel, and their distance-dependent changes in spreading velocity was consistent with that in lipid bilayer. Next, the lipid layer was characterized with fluorescence recovery after photo breaching experiment. As a result, it is indicated that lipid molecules in the lipid layer on the agarose showed lateral diffusion, a typical characteristic of lipid bilayer. Taken together, we confirmed that lipid bilayer can be formed on the patterned agarose gel with self-spreading method. The hydrogel-supported bilayer will be a suitable tool for drug discovery.

  10. Simple agarose micro-confinement array and machine-learning-based classification for analyzing the patterned differentiation of mesenchymal stem cells.

    Directory of Open Access Journals (Sweden)

    Nobuyuki Tanaka

    Full Text Available The geometrical confinement of small cell colonies gives differential cues to cells sitting at the periphery versus the core. To utilize this effect, for example to create spatially graded differentiation patterns of human mesenchymal stem cells (hMSCs in vitro or to investigate underpinning mechanisms, the confinement needs to be robust for extended time periods. To create highly repeatable micro-fabricated structures for cellular patterning and high-throughput data mining, we employed here a simple casting method to fabricate more than 800 adhesive patches confined by agarose micro-walls. In addition, a machine learning based image processing software was developed (open code to detect the differentiation patterns of the population of hMSCs automatically. Utilizing the agarose walls, the circular patterns of hMSCs were successfully maintained throughout 15 days of cell culture. After staining lipid droplets and alkaline phosphatase as the markers of adipogenic and osteogenic differentiation, respectively, the mega-pixels of RGB color images of hMSCs were processed by the software on a laptop PC within several minutes. The image analysis successfully showed that hMSCs sitting on the more central versus peripheral sections of the adhesive circles showed adipogenic versus osteogenic differentiation as reported previously, indicating the compatibility of patterned agarose walls to conventional microcontact printing. In addition, we found a considerable fraction of undifferentiated cells which are preferentially located at the peripheral part of the adhesive circles, even in differentiation-inducing culture media. In this study, we thus successfully demonstrated a simple framework for analyzing the patterned differentiation of hMSCs in confined microenvironments, which has a range of applications in biology, including stem cell biology.

  11. A lightweight scalable agarose-gel-synthesized thermoelectric composite

    Science.gov (United States)

    Kim, Jin Ho; Fernandes, Gustavo E.; Lee, Do-Joong; Hirst, Elizabeth S.; Osgood, Richard M., III; Xu, Jimmy

    2018-03-01

    Electronic devices are now advancing beyond classical, rigid systems and moving into lighweight flexible regimes, enabling new applications such as body-wearables and ‘e-textiles’. To support this new electronic platform, composite materials that are highly conductive yet scalable, flexible, and wearable are needed. Materials with high electrical conductivity often have poor thermoelectric properties because their thermal transport is made greater by the same factors as their electronic conductivity. We demonstrate, in proof-of-principle experiments, that a novel binary composite can disrupt thermal (phononic) transport, while maintaining high electrical conductivity, thus yielding promising thermoelectric properties. Highly conductive Multi-Wall Carbon Nanotube (MWCNT) composites are combined with a low-band gap semiconductor, PbS. The work functions of the two materials are closely matched, minimizing the electrical contact resistance within the composite. Disparities in the speed of sound in MWCNTs and PbS help to inhibit phonon propagation, and boundary layer scattering at interfaces between these two materials lead to large Seebeck coefficient (> 150 μV/K) (Mott N F and Davis E A 1971 Electronic Processes in Non-crystalline Materials (Oxford: Clarendon), p 47) and a power factor as high as 10 μW/(K2 m). The overall fabrication process is not only scalable but also conformal and compatible with large-area flexible hosts including metal sheets, films, coatings, possibly arrays of fibers, textiles and fabrics. We explain the behavior of this novel thermoelectric material platform in terms of differing length scales for electrical conductivity and phononic heat transfer, and explore new material configurations for potentially lightweight and flexible thermoelectric devices that could be networked in a textile.

  12. Hydrolysis of proteins by immobilized-stabilized alcalase-glyoxyl agarose.

    Science.gov (United States)

    Tardioli, Paulo W; Pedroche, Justo; Giordano, Raquel L C; Fernández-Lafuente, Roberto; Guisán, José M

    2003-01-01

    This paper presents stable Alcalase-glyoxyl derivatives, to be used in the controlled hydrolysis of proteins. They were produced by immobilizing-stabilizing Alcalase on cross-linked 10% agarose beads, using low and high activation grades of the support and different immobilization times. The Alcalase glyoxyl derivatives were compared to other agarose derivatives, prepared using glutaraldehyde and CNBr as activation reactants. The performance of derivatives in the hydrolysis of casein was also tested. At pH 8.0 and 50 degrees C, Alcalase derivatives produced with 1 h of immobilization time on agarose activated with glutaraldehyde, CNBr, and low and high glyoxyl groups concentration presented half-lives of ca. 10, 29, 60, and 164 h, respectively. More extensive immobilization monotonically led to higher stabilization. The most stabilized Alcalase-glyoxyl derivative was produced using 96 h of immobilization time and high activation grade of the support. It presented half-life of ca. 23 h, at pH 8.0 and 63 degrees C and was ca. 500-fold more stable than the soluble enzyme. Thermal inactivation of all derivatives followed a single-step non-first-order kinetics. The most stable derivative presented ca. 54% of the activity of the soluble enzyme for the hydrolysis of casein and of the small substrate Boc-Ala-ONp. This behavior suggests that the decrease in activity was due to enzyme distortion but not to wrong orientation. The hydrolysis degree of casein at 80 degrees C with the most stabilized enzyme was 2-fold higher than that achieved using soluble enzyme, as a result of the thermal inactivation of the latter. Therefore, the high stability of the new Alcalase-glyoxyl derivative allows the design of continuous processes to hydrolyze proteins at temperatures that avoid microbial growth.

  13. Microneedle assisted micro-particle delivery from gene guns: experiments using skin-mimicking agarose gel.

    Science.gov (United States)

    Zhang, Dongwei; Das, Diganta B; Rielly, Chris D

    2014-02-01

    A set of laboratory experiments has been carried out to determine if micro-needles (MNs) can enhance penetration depths of high-speed micro-particles delivered by a type of gene gun. The micro-particles were fired into a model target material, agarose gel, which was prepared to mimic the viscoelastic properties of porcine skin. The agarose gel was chosen as a model target as it can be prepared as a homogeneous and transparent medium with controllable and reproducible properties allowing accurate determination of penetration depths. Insertions of various MNs into gels have been analysed to show that the length of the holes increases with an increase in the agarose concentration. The penetration depths of micro-particle were analysed in relation to a number of variables, namely the operating pressure, the particle size, the size of a mesh used for particle separation and the MN dimensions. The results suggest that the penetration depths increase with an increase of the mesh pore size, because of the passage of large agglomerates. As these particles seem to damage the target surface, then smaller mesh sizes are recommended; here, a mesh with a pore size of 178 μm was used for the majority of the experiments. The operating pressure provides a positive effect on the penetration depth, that is it increases as pressure is increased. Further, as expected, an application of MNs maximises the micro-particle penetration depth. The maximum penetration depth is found to increase as the lengths of the MNs increase, for example it is found to be 1272 ± 42, 1009 ± 49 and 656 ± 85 μm at 4.5 bar pressure for spherical micro-particles of 18 ± 7 μm diameter when we used MNs of 1500, 1200 and 750 μm length, respectively. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  14. Novel neonicotinoid-agarose affinity column for Drosophila and Musca nicotinic acetylcholine receptors.

    Science.gov (United States)

    Tomizawa, M; Latli, B; Casida, J E

    1996-10-01

    Neonicotinoids such as the insecticide imidacloprid (IMI) act as agonists at the insect nicotinic acetylcholine receptor (nAChR). Head membranes of Drosophila melanogaster and Musca domestica have a single high-affinity binding site for [3H]IMI with KD values of 1-2 nM and Bmax values of 560-850 fmol/mg of protein. Locusta and Periplaneta nAChRs isolated with an alpha-bungarotoxin (alpha-BGT)-agarose affinity column are known to be alpha-subunit homooligomers. This study uses 1-[N-(6-chloro-3-pyridylmethyl)-N-ethyl]amino-1-amino-2-nitroethene++ + (which inhibits [3H]IMI binding to Drosophila and Musca head membranes at 2-3 nM) to develop a neonicotinoid-agarose affinity column. The procedure-introduction of Triton-solubilized Drosophila or Musca head membranes into this neonicotinoid-based column, elution with IMI, and analysis by lithium dodecyl sulfate-polyacrylamicle gel electrophoresis-gives only three proteins (69, 66, and 61 kDa) tentatively assigned as putative subunits of the nAChR; the same three proteins are obtained with Musca using the alpha-BGT-agarose affinity column. Photoaffinity labeling of the Drosophila and Musca putative subunits from the neonicotinoid column with 125I-alpha-BGT-4-azidosalicylic acid gives a labeled derivative of 66-69 kDa. The yield is 2-5 micrograms of receptor protein from 1 g of Drosophila or Musca heads. Neonicotinoid affinity chromatography to isolate native Drosophila and Musca receptors will facilitate studies on the structure and function of insect nAChRs.

  15. Acoustic transfer of protein crystals from agarose pedestals to micromeshes for high-throughput screening

    Energy Technology Data Exchange (ETDEWEB)

    Cuttitta, Christina M. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); The City University of New York, 2800 Victory Boulevard, Staten Island, NY 10314 (United States); Ericson, Daniel L. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); University at Buffalo, SUNY, 12 Capen Hall, Buffalo, NY 14260 (United States); Scalia, Alexander [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Binghamton University, 4400 Vestal Parkway East, Binghamton, NY 11973-5000 (United States); Roessler, Christian G. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Teplitsky, Ella [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Stony Brook University, Stony Brook, NY 11794-5215 (United States); Joshi, Karan [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); PEC University of Technology, Chandigarh (India); Campos, Olven [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33414 (United States); Agarwal, Rakhi; Allaire, Marc [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Orville, Allen M. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Sweet, Robert M.; Soares, Alexei S., E-mail: soares@bnl.gov [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)

    2015-01-01

    An acoustic high-throughput screening method is described for harvesting protein crystals and combining the protein crystals with chemicals such as a fragment library. Acoustic droplet ejection (ADE) is an emerging technology with broad applications in serial crystallography such as growing, improving and manipulating protein crystals. One application of this technology is to gently transfer crystals onto MiTeGen micromeshes with minimal solvent. Once mounted on a micromesh, each crystal can be combined with different chemicals such as crystal-improving additives or a fragment library. Acoustic crystal mounting is fast (2.33 transfers s{sup −1}) and all transfers occur in a sealed environment that is in vapor equilibrium with the mother liquor. Here, a system is presented to retain crystals near the ejection point and away from the inaccessible dead volume at the bottom of the well by placing the crystals on a concave agarose pedestal (CAP) with the same chemical composition as the crystal mother liquor. The bowl-shaped CAP is impenetrable to crystals. Consequently, gravity will gently move the crystals into the optimal location for acoustic ejection. It is demonstrated that an agarose pedestal of this type is compatible with most commercially available crystallization conditions and that protein crystals are readily transferred from the agarose pedestal onto micromeshes with no loss in diffraction quality. It is also shown that crystals can be grown directly on CAPs, which avoids the need to transfer the crystals from the hanging drop to a CAP. This technology has been used to combine thermolysin and lysozyme crystals with an assortment of anomalously scattering heavy atoms. The results point towards a fast nanolitre method for crystal mounting and high-throughput screening.

  16. Pellet pestle homogenization of agarose gel slices at 45 degrees C for deoxyribonucleic acid extraction.

    Science.gov (United States)

    Kurien, B T; Kaufman, K M; Harley, J B; Scofield, R H

    2001-09-15

    A simple method for extracting DNA from agarose gel slices is described. The extraction is rapid and does not involve harsh chemicals or sophisticated equipment. The method involves homogenization of the excised gel slice (in Tris-EDTA buffer), containing the DNA fragment of interest, at 45 degrees C in a microcentrifuge tube with a Kontes pellet pestle for 1 min. The "homogenate" is then centrifuged for 30 s and the supernatant is saved. The "homogenized" agarose is extracted one more time and the supernatant obtained is combined with the previous supernatant. The DNA extracted using this method lent itself to restriction enzyme analysis, ligation, transformation, and expression of functional protein in bacteria. This method was found to be applicable with 0.8, 1.0, and 2.0% agarose gels. DNA fragments varying from 23 to 0.4 kb were extracted using this procedure and a yield ranging from 40 to 90% was obtained. The yield was higher for fragments 2.0 kb and higher (70-90%). This range of efficiency was maintained when the starting material was kept between 10 and 300 ng. The heat step was found to be critical since homogenization at room temperature failed to yield any DNA. Extracting DNA with our method elicited an increased yield (up to twofold) compared with that extracted with a commercial kit. Also, the number of transformants obtained using the DNA extracted with our method was at least twice that obtained using the DNA extracted with the commercial kit. Copyright 2001 Academic Press.

  17. Generation of Multicellular Tumor Spheroids with Microwell-Based Agarose Scaffolds for Drug Testing.

    Directory of Open Access Journals (Sweden)

    Xue Gong

    Full Text Available Three dimensional multicellular aggregate, also referred to as cell spheroid or microtissue, is an indispensable tool for in vitro evaluating antitumor activity and drug efficacy. Compared with classical cellular monolayer, multicellular tumor spheroid (MCTS offers a more rational platform to predict in vivo drug efficacy and toxicity. Nevertheless, traditional processing methods such as plastic dish culture with nonadhesive surfaces are regularly time-consuming, laborious and difficult to provide uniform-sized spheroids, thus causing poor reproducibility of experimental data and impeding high-throughput drug screening. In order to provide a robust and effective platform for in vitro drug evaluation, we present an agarose scaffold prepared with the template containing uniform-sized micro-wells in commercially available cell culture plates. The agarose scaffold allows for good adjustment of MCTS size and large-scale production of MCTS. Transparent agarose scaffold also allows for monitoring of spheroid formation under an optical microscopy. The formation of MCTS from MCF-7 cells was prepared using different-size-well templates and systematically investigated in terms of spheroid growth curve, circularity, and cell viability. The doxorubicin cytotoxicity against MCF-7 spheroid and MCF-7 monolayer cells was compared. The drug penetration behavior, cell cycle distribution, cell apoptosis, and gene expression were also evaluated in MCF-7 spheroid. The findings of this study indicate that, compared with cellular monolayer, MCTS provides a valuable platform for the assessment of therapeutic candidates in an in vivo-mimic microenvironment, and thus has great potential for use in drug discovery and tumor biology research.

  18. Acoustic transfer of protein crystals from agarose pedestals to micromeshes for high-throughput screening

    Science.gov (United States)

    Cuttitta, Christina M.; Ericson, Daniel L.; Scalia, Alexander; Roessler, Christian G.; Teplitsky, Ella; Joshi, Karan; Campos, Olven; Agarwal, Rakhi; Allaire, Marc; Orville, Allen M.; Sweet, Robert M.; Soares, Alexei S.

    2015-01-01

    Acoustic droplet ejection (ADE) is an emerging technology with broad applications in serial crystallography such as growing, improving and manipulating protein crystals. One application of this technology is to gently transfer crystals onto MiTeGen micromeshes with minimal solvent. Once mounted on a micromesh, each crystal can be combined with different chemicals such as crystal-improving additives or a fragment library. Acoustic crystal mounting is fast (2.33 transfers s−1) and all transfers occur in a sealed environment that is in vapor equilibrium with the mother liquor. Here, a system is presented to retain crystals near the ejection point and away from the inaccessible dead volume at the bottom of the well by placing the crystals on a concave agarose pedestal (CAP) with the same chemical composition as the crystal mother liquor. The bowl-shaped CAP is impenetrable to crystals. Consequently, gravity will gently move the crystals into the optimal location for acoustic ejection. It is demonstrated that an agarose pedestal of this type is compatible with most commercially available crystallization conditions and that protein crystals are readily transferred from the agarose pedestal onto micromeshes with no loss in diffraction quality. It is also shown that crystals can be grown directly on CAPs, which avoids the need to transfer the crystals from the hanging drop to a CAP. This technology has been used to combine thermolysin and lysozyme crystals with an assortment of anomalously scattering heavy atoms. The results point towards a fast nanolitre method for crystal mounting and high-throughput screening. PMID:25615864

  19. Arthromyces and Blastosporella, two new genera of conidia-producing lyophylloid agarics (Agaricales, Basidiomycota) from the neotropics.

    Science.gov (United States)

    Baroni, Timothy J; Franco-Molano, Ana Esperanza; Lodge, D Jean; Lindner, Daniel L; Horak, Egon; Hofstetter, Valerie

    2007-05-01

    Two new genera encompassing three new species of lyophylloid agarics that produce conidia on the basidiomata are described. Arthromyces is a genus comprised of two very different arthrospore-producing mushroom species found in the Greater Antilles and Central America. Blastosporella is a monotypic genus with spherical balls of blastospores covering the pileus surface with age and is known from Hispaniola and Colombia. A key to the species of Arthromyces is included.

  20. Comparison of two commercial formulations of the MacConkey agar test for mycobacteria.

    Science.gov (United States)

    Kubica, G P; Vitvitsky, J

    1974-05-01

    Recent evaluations of the MacConkey agar test for differentiation of rapidly growing mycobacteria have revealed that certain strains of Mycobacterium fortuitum and M. chelonei that were expected to grow on MacConkey agar failed to do so. Investigation of two formulations of MacConkey agar showed that these two species grew better on the medium when the crystal violet dye was omitted. Several possible reasons for this difficulty are discussed. It is recommended that clinical laboratories engaged in differential identification of mycobacteria utilize commercial MacConkey agar without crystal violet when testing rapidly growing species of this genus.

  1. EVALUACIÓN POR MÉTODO ECOMÉTRICO DE AGAR OBTENIDO DE ALGAS ROJAS COLOMBIANAS

    Directory of Open Access Journals (Sweden)

    A. Villalobos

    2007-12-01

    Full Text Available The purpose of this study was to evaluate the productivity on agar-agar of two species of red algae of thegenera Gracilaria belonging from the Colombiam Caribean coast (G. cylindrica and G. mammillarisobtained in laboratory. Productivity of culture media elaborated with base agar - agar was determinedusing the ecometric method with 20 different bacterial species. Results obtained from ICA and ICRshowed that agar extracted from Gracilaria cylindrica and Gracillaria mammillaris are equally productive,this shows that both species can be used for agar production. For better results, it is still necessary tooptimize extraction processes and purification of agar in both species of algae.

  2. Method for resolution and western blotting of very large proteins using agarose electrophoresis.

    Science.gov (United States)

    Greaser, Marion L; Warren, Chad M

    2015-01-01

    Proteins larger than 200 kDa are difficult to separate electrophoretically using polyacrylamide gels, and their transfer during western blotting is typically incomplete. A vertical SDS agarose gel system was developed that has vastly improved resolving power for very large proteins. Complete transfer of proteins as large as titin (Mr 3,000-3,700 kDa) onto blots can be achieved. The addition of a sulfhydryl reducing agent in the upper reservoir buffer and transfer buffer markedly improves the blotting of large proteins.

  3. Green synthesis of gold nanoparticles of different sizes and shapes using agar-agar water solution and femtosecond pulse laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Almeida de Matos, Ricardo [Universidade Federal de Sao Paulo (UNIFESP) - Campus Diadema, Instituto de Ciencias Ambientais, Quimicas e Farmaceuticas (ICAQF), Departamento de Ciencias Exatas e da Terra (DCET), Diadema, SP (Brazil); Universidade Federal de Sao Paulo - UNIFESP, Sao Paulo (Brazil); Silva Cordeiro, Thiago da; Elgul Samad, Ricardo; Dias Vieira, Nilson [Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP, Sao Paulo (Brazil); Coronato Courrol, Lilia [Universidade Federal de Sao Paulo - UNIFESP, Sao Paulo (Brazil); Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP, Sao Paulo (Brazil)

    2012-11-15

    We report a method to create gold nanoparticles of different sizes and shapes using agar-agar water solution and irradiation with light from a xenon lamp, followed by ultrashort laser pulses. No additives, such as solvents, surfactants or reducing agents, were used in the procedure. Laser irradiation (laser ablation) was important to the reduction of the nanoparticles diameter and formation of another shapes. Distilled water was used as solvent and agar-agar (hydrophilic colloid extracted from certain seaweeds) was important for the stabilization of gold nanoparticles, avoiding their agglomeration. The formation of gold nanoparticles was confirmed with ultraviolet-visible absorption and TEM microscopy. The gold nanoparticles acquired spherical, prism, and rod shapes depending on the laser parameters. Variation of laser irradiation parameters as pulse energy, irradiation time and repetition rate was assessed. The relevant mechanisms contributing for the gold nanoparticles production are discussed. (orig.)

  4. Agarose-chitosan-C18film micro-solid phase extraction combined with high performance liquid chromatography for the determination of phenanthrene and pyrene in chrysanthemum tea samples.

    Science.gov (United States)

    Ng, Nyuk Ting; Sanagi, Mohd Marsin; Wan Ibrahim, Wan Nazihah; Wan Ibrahim, Wan Aini

    2017-05-01

    Agarose-chitosan-immobilized octadecylsilyl-silica (C 18 ) film micro-solid phase extraction (μSPE) was developed and applied for the determination of phenanthrene (PHE) and pyrene (PYR) in chrysanthemum tea samples using high performance liquid chromatography-ultraviolet detection (HPLC-UV). The film of blended agarose and chitosan allows good dispersion of C 18 , prevents the leaching of C 18 during application and enhances the film mechanical stability. Important μSPE parameters were optimized including amount of sorbent loading, extraction time, desorption solvent and desorption time. The matrix match calibration curves showed good linearity (r⩾0.994) over a concentration range of 1-500ppb. Under the optimized conditions, the proposed method showed good limits of detection (0.549-0.673ppb), good analyte recoveries (100.8-105.99%) and good reproducibilities (RSDs⩽13.53%, n=3) with preconcentration factors of 4 and 72 for PHE and PYR, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Evaluation of a capillary zone electrophoresis system versus a conventional agarose gel system for routine serum protein separation and monoclonal component typing.

    Science.gov (United States)

    Roudiere, L; Boularan, A M; Bonardet, A; Vallat, C; Cristol, J P; Dupuy, A M

    2006-01-01

    Capillary zone electrophoresis of serum proteins is increasingly gaining impact in clinical laboratories. During 2003, we compared the fully automated capillary electrophoresis (CE) system from Beckman (Paragon CZE 2000) with the method agarose gel electrophoresis Sebia (Hydrasis-Hyris, AGE). This new study focused on the evaluation of analytical performance and a comparison including 115 fresh routine samples (group A) and a series of 97 frozen pathologic sera with suspicion of monoclonal protein (group B). Coefficients of variation (CVs %) for the five classical protein fractions have been reported to be consistenly serum samples (group B), there were 90 in which we detected a monoclonal protein by immunofixation (IF) (immunosubtraction (IS) was not used). AGE and Paragon 2000 failed to detect 7 and 12 monoclonal proteins, respectively, leading to a concordance to 92% for AGE and 87% for Paragon 2000 for identifying electrophoretic abnormalities in this group. Beta-globulin abnormalities and M paraprotein were well detected with Paragon 2000. Only 81% (21 vs 26) of the gammopathies were immunotyped with IS by two readers blinded to the IF immunotype. The Paragon 2000 is a reliable alternative to conventional agarose gel electrophoresis combining the advantages of full automation (rapidity, ease of use and cost) with high analytical performance. Qualified interpretation of results requires an adaptation period which could further improve concordance between the methods. Recently, this CE system has been improved by the manufacturer (Beckman) concerning the migration buffer and detection of beta-globulin abnormalities.

  6. Pulsed photothermal temperature profiling of agar tissue phantoms.

    Science.gov (United States)

    Milanic, Matija; Majaron, Boris; Nelson, J Stuart

    2007-11-01

    We determine experimentally the accuracy of pulsed photothermal radiometric (PPTR) temperature depth profiling in water-based samples. We use custom tissue phantoms composed of agar gel layers separated by very thin absorbing layers. Two configurations of the acquisition system are compared, one using the customary spectral band of the InSb radiation detector (3.0-5.5 microm) and the other with a spectrally narrowed acquisition band (4.5-5.5 microm). The laser-induced temperature depth profiles are reconstructed from measured radiometric signals using a custom minimization algorithm. The results correlate very well with phantom geometry as determined by optical coherence tomography (OCT) and histology in all evaluated samples. Determination of the absorbing layer depth shows good repeatability with spatial resolution decreasing with depth. Spectral filtering improves the accuracy and resolution, especially for shallow absorption layers (~120 microm) and more complex structures (e.g., with two absorbing layers). The average full width at half maximum (FWHM) of the temperature peaks equals 23% of the layer depth.

  7. Agar dilution method for susceptibility testing of Neisseria gonorrhoeae

    Directory of Open Access Journals (Sweden)

    Marta C de Castillo

    1996-12-01

    Full Text Available The antibiotic susceptibilities of Neisseria gonorrhoeae isolates obtained from patients attending a clinic for sexually transmitted diseases in Tucumán, Argentina, were determined by the agar dilution method (MIC. 3.5% of the isolates produced ²-lactamase. A total of 96.5% of ²-lactamase negative isolates tested were susceptible to penicillin (MIC < 2 µgml-1; 14.03% of the tested isolates were resistant to tetracycline (MIC < 2 µgml-1, and 98% of the tested isolates were susceptible to spectinomycin (MIC < 64 µgml-1. The MICs for 95% of the isolates, tested for other drugs were: < 2 µgml-1 for cefoxitin, < 0.06 µgml-1 for cefotaxime, < 0.25 µgml-1 for norfloxacin, < 10 µgml-1 for cephaloridine, < 10 µgml-1 for cephalexin, and < 50 µgml-1 for kanamycin. Antibiotic resistance among N. gonorrhoeae isolates from Tucumán, Argentina, appeared to be primarily limited to penicillin and tetracycline, which has been a general use against gonorrhoeae in Tucumán since 1960. Periodic monitoring of the underlying susceptibility profiles of the N. gonorrhoeae strains prevalent in areas of frequent transmission may provide clues regarding treatment options and emerging of drug resistance.

  8. Glucose-sucrose-potassium tellurite-bacitracin agar, an alternative to mitis salivarius-bacitracin agar for enumeration of Streptococcus mutans.

    OpenAIRE

    Tanzer, J M; Börjesson, A C; Laskowski, L; Kurasz, A B; Testa, M

    1984-01-01

    An agar medium for selective recovery and enumeration of Streptococcus mutans was developed as an alternative to mitis salivarius-bacitracin (MSB) agar. Combinations of dyes, antibiotics, and tellurite were added to a nonselective medium which, because of its sucrose content, allowed easy recognition of S. mutans colonies. Candle jar incubation for 2 days, by comparison with anaerobic incubation, reduced background flora but did not diminish S. mutans recoveries from clinical samples. Quantit...

  9. Glucose-sucrose-potassium tellurite-bacitracin agar, an alternative to mitis salivarius-bacitracin agar for enumeration of Streptococcus mutans.

    Science.gov (United States)

    Tanzer, J M; Börjesson, A C; Laskowski, L; Kurasz, A B; Testa, M

    1984-10-01

    An agar medium for selective recovery and enumeration of Streptococcus mutans was developed as an alternative to mitis salivarius-bacitracin (MSB) agar. Combinations of dyes, antibiotics, and tellurite were added to a nonselective medium which, because of its sucrose content, allowed easy recognition of S. mutans colonies. Candle jar incubation for 2 days, by comparison with anaerobic incubation, reduced background flora but did not diminish S. mutans recoveries from clinical samples. Quantitative comparisons were made of the simultaneous recoveries of a number of authentic S. mutans serotype representatives and fresh clinical isolates, using various glucose-sucrose-potassium tellurite-bacitracin (GSTB) formulations and mitis salivarius, MSB, and blood agars. Mitis salivarius counts were not detectably different from blood counts, but counts on MSB were distinctly lower. A formulation of the new medium containing 5% glucose 5% sucrose, 0.001% potassium tellurite, 0.3 U of bacitracin per ml (hence GSTB), and 2% agar gave recoveries nearly equal to those on mitis salivarius agar and much greater than those on MSB. The medium yielded readily recognized S. mutans colonies and facilitated detection of intracellular polysaccharide formers upon flooding with I2 reagent. Freshly isolated serotype c, E, and f colonies could often be distinguished from serotype d and g colonies, a distinction made reliable by testing for intracellular polysaccharide. A study of 300 salivary samples revealed GSTB to give significantly higher recoveries than MSB. About 72% of all samples were substantially underestimated for S. mutans with MSB, and 6.7% of samples were falsely negative for S. mutans with MSB. Recovery of background flora on GSTB was as low or lower than on MSB, and both types of agar could be stored for at least 9 weeks without notable change of selectivity. Thus, GSTB agar appears to be simple and reliable to use and requires no anaerobic incubation. Caution is voiced about

  10. Tailor-made cell patterning using a near-infrared-responsive composite gel composed of agarose and carbon nanotubes

    International Nuclear Information System (INIS)

    Koga, Haruka; Nakazawa, Kohji; Sada, Takao; Fujigaya, Tsuyohiko; Nakashima, Naotoshi

    2013-01-01

    Micropatterning is useful for regulating culture environments. We developed a highly efficient near-infrared-(NIR)-responsive gel and established a new technique that enables cell patterning by NIR irradiation. As a new culture substratum, we designed a tissue culture plate that was coated with a composite gel composed of agarose and carbon nanotubes (CNTs). A culture plate coated with agarose only showed no response to NIR irradiation. In contrast, NIR laser irradiation induced heat generation by CNTs; this permitted local solation of the CNT/agarose gel, and consequently, selective cell-adhesive regions were exposed on the tissue culture plate. The solation area was controlled by the NIR intensity, magnification of the object lens and CNT concentration in the gel. Furthermore, we formed circular patterns of HeLa cells and linear patterns of 3T3 cells on the same culture plate through selective and stepwise NIR irradiation of the CNT/agarose gel, and we also demonstrated that individual 3T3 cells migrated along a linear path formed on the CNT/agarose gel by NIR irradiation. These results indicate that our technique is useful for tailor-made cell patterning of stepwise and/or complex cell patterns, which has various biological applications such as stepwise co-culture and the study of cell migration. (paper)

  11. A novel phylogeny of the Gelidiales (Rhodophyta) based on five genes including the nuclear CesA, with descriptions of Orthogonacladia gen. nov. and Orthogonacladiaceae fam. nov.

    Science.gov (United States)

    Boo, Ga Hun; Le Gall, Line; Miller, Kathy Ann; Freshwater, D Wilson; Wernberg, Thomas; Terada, Ryuta; Yoon, Kyung Ju; Boo, Sung Min

    2016-08-01

    Although the Gelidiales are economically important marine red algae producing agar and agarose, the phylogeny of this order remains poorly resolved. The present study provides a molecular phylogeny based on a novel marker, nuclear-encoded CesA, plus plastid-encoded psaA, psbA, rbcL, and mitochondria-encoded cox1 from subsets of 107 species from all ten genera within the Gelidiales. Analyses of individual and combined datasets support the monophyly of three currently recognized families, and reveal a new clade. On the basis of these results, the new family Orthogonacladiaceae is described to accommodate Aphanta and a new genus Orthogonacladia that includes species previously classified as Gelidium madagascariense and Pterocladia rectangularis. Acanthopeltis is merged with Gelidium, which has nomenclatural priority. Nuclear-encoded CesA was found to be useful for improving the resolution of phylogenetic relationships within the Gelidiales and is likely to be valuable for the inference of phylogenetic relationship among other red algal taxa. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. The effect of magnetic nanoparticles on the acoustic properties of tissue-mimicking agar-gel phantoms

    Science.gov (United States)

    Józefczak, A.; Kaczmarek, K.; Kubovčíková, M.; Rozynek, Z.; Hornowski, T.

    2017-06-01

    In ultrasonic hyperthermia, ultrasound-induced heating is achieved by the absorption of wave energy and its conversion into heat. The effectiveness of ultrasounds can be improved by using sonosensitisers that greatly attenuate ultrasonic waves and then dissipate the acquired energy in the form of heat. One possible candidate for such a sonosensitiser are superparamagnetic iron oxide nanoparticles. Here, we used magnetic nanoparticles embedded in a tissue-mimicking agar-gel matrix. Such tissue-mimicking phantoms possess acoustic properties similar to those of real tissues, and are used as a tool for performance testing and optimisation of medical ultrasound systems. In this work, we studied the effect of magnetic nanoparticles on the acoustic properties of agar-gel phantoms, including the attenuation of ultrasonic waves.

  13. Pravastatin Improves Glucose Regulation and Biocompatibility of Agarose Encapsulated Porcine Islets following Transplantation into Pancreatectomized Dogs

    Directory of Open Access Journals (Sweden)

    Lawrence S. Gazda

    2014-01-01

    Full Text Available The encapsulation of porcine islets is an attractive methodology for the treatment of Type I diabetes. In the current study, the use of pravastatin as a mild anti-inflammatory agent was investigated in pancreatectomized diabetic canines transplanted with porcine islets encapsulated in agarose-agarose macrobeads and given 80 mg/day of pravastatin (n=3 while control animals did not receive pravastatin (n=3. Control animals reached preimplant insulin requirements on days 18, 19, and 32. Pravastatin-treated animals reached preimplant insulin requirements on days 22, 27, and 50. Two animals from each group received a second macrobead implant: control animals remained insulin-free for 15 and 21 days (AUC = 3003 and 5078 mg/dL/24 hr days 1 to 15 and reached preimplant insulin requirements on days 62 and 131. Pravastatin treated animals remained insulin-free for 21 and 34 days (AUC = 1559 and 1903 mg/dL/24 hr days 1 to 15 and reached preimplant insulin requirements on days 38 and 192. Total incidence (83.3% versus 64.3% and total severity (22.7 versus 18.3 of inflammation on tissue surfaces were higher in the control group at necropsy. These findings support pravastatin therapy in conjunction with the transplantation of encapsulated xenogeneic islets for the treatment of diabetes mellitus.

  14. Use of a commercial agarose gel for analysis of urinary glycosaminoglycans in mucopolysaccharidoses

    Directory of Open Access Journals (Sweden)

    Ana Carolina Breier

    Full Text Available ABSTRACT Mucopolysaccharidoses (MPS are a group of inherited metabolic disorders caused by deficiency of enzymes that degrade glycosaminoglycans (GAGs. Urinary excretion of GAGs is a common feature of MPS, and is considered their major biomarker. We aimed to adapt the GAG electrophoresis method to a commercial agarose gel which would be able to separate urinary GAGs in a simpler way with good sensitivity and reproducibility. Urine samples from patients previously diagnosed with MPS I, IV, and VI were used as electrophoretic standards. Samples from patients on enzyme replacement therapy (ERT were also assessed. Commercial agarose gel electrophoresis was effective, showing proper definition and separation of GAG bands. Detection sensitivity exceeded 0.1 µg and band reproducibility were consistent. GAG bands quantified in urine samples from patients on ERT correlated very strongly (correlation coefficient = 0.98 with total GAG concentrations. This application of gel electrophoresis demonstrates the possibility of monitoring patients with MPS treated with ERT by analyzing separately the GAGs excreted in urine. We suggest this process should be applied to MPS screening as well as to follow-up of patients on treatment.

  15. Agarose gel-coated LPG based on two sensing mechanisms for relative humidity measurement.

    Science.gov (United States)

    Miao, Yinping; Zhang, Kaikiang; Yuam, Yujie; Liu, Bo; Zhang, Hao; Liu, Yan; Yao, Jianquan

    2013-01-01

    A relative humidity (RH) sensor based on long-period grating (LPG) with different responses is proposed by utilizing agarose gel as the sensitive cladding film. The spectral characteristic is discussed as the ambient humidity level ranges from 25% to 95% RH. Since increment of RH will result in volume expansion and refractive index increment of the agarose gel, the LPG is sensitive to applied strain and ambient refractive index; both the resonance wavelength and coupling intensity present particular responses to RH within two different RH ranges (25%-65% RH and 65%-96% RH). The coupling intensity decreases within a lower RH range while it increases throughout a higher RH range. The resonance wavelength is sensitive to the higher RH levels, and the highest sensitivity reaches 114.7 pm/% RH, and shares the same RH turning point with coupling intensity response. From a practical perspective, the proposed RH sensor would find its potential applications in high humidity level, temperature-independent RH sensing and multiparameter sensing based on wavelength/power hybrid demodulation and even static RH alarm for automatic monitoring of a particular RH value owing to the nonmonotonic RH dependence of the transmission power within the whole tested RH range.

  16. Inhibition of Streptococcus mutans strains by different mitis-salivarius agar preparations.

    Science.gov (United States)

    Staat, R H

    1976-03-01

    Several Streptococcus mutans strains were markedly inhibited by mitis-salivarius agar manufactured by Baltimore Biological Laboratories, but little, if any, inhibition was noted using Difco Laboratories' mitis-salivarius agar. Supplementation of the basic medium with sucrose and bacitracin for specific selection of S. mutans resulted in suppression of representative S. mutans type a strains regardless of manufacturer.

  17. Use of cefoperazone MacConkey agar for selective isolation of Laribacter hongkongensis.

    Science.gov (United States)

    Lau, Susanna K P; Woo, Patrick C Y; Hui, Wai-ting; Li, Maria W S; Teng, Jade L L; Que, Tak-Lun; Luk, Wei-Kwang; Lai, Raymond W M; Yung, Raymond W H; Yuen, Kwok-yung

    2003-10-01

    A new selective medium, cefoperazone MacConkey agar (CMA), was developed for primary isolation of Laribacter hongkongensis from stool. Its performance in quantitative recovery and in a clinical evaluation of 4,741 human diarrheal stool specimens was superior to that of charcoal cefoperazone deoxycholate agar. In addition, with CMA, Arcobacter butzleri was unexpectedly isolated from the stools of six patients.

  18. Use of Cefoperazone MacConkey Agar for Selective Isolation of Laribacter hongkongensis

    OpenAIRE

    Lau, Susanna K. P.; Woo, Patrick C. Y.; Hui, Wai-ting; Li, Maria W. S.; Teng, Jade L. L.; Que, Tak-Lun; Luk, Wei-Kwang; Lai, Raymond W. M.; Yung, Raymond W. H.; Yuen, Kwok-yung

    2003-01-01

    A new selective medium, cefoperazone MacConkey agar (CMA), was developed for primary isolation of Laribacter hongkongensis from stool. Its performance in quantitative recovery and in a clinical evaluation of 4,741 human diarrheal stool specimens was superior to that of charcoal cefoperazone deoxycholate agar. In addition, with CMA, Arcobacter butzleri was unexpectedly isolated from the stools of six patients.

  19. Genome sequence of the agar-degrading marine bacterium Alteromonadaceae sp. strain G7.

    Science.gov (United States)

    Kwak, Min-Jung; Song, Ju Yeon; Kim, Byung Kwon; Chi, Won-Jae; Kwon, Soon-Kyeong; Choi, Soobeom; Chang, Yong-Keun; Hong, Soon-Kwang; Kim, Jihyun F

    2012-12-01

    Here, we present the high-quality draft genome sequence of the agar-degrading marine gammaproteobacterium Alteromonadaceae sp. strain G7, which was isolated from coastal seawater to be utilized as a bioresource for production of agar-derived biofuels. The 3.91-Mb genome contains a number of genes encoding algal polysaccharide-degrading enzymes such as agarases and sulfatases.

  20. Genome Sequence of the Agar-Degrading Marine Bacterium Alteromonadaceae sp. Strain G7

    OpenAIRE

    Kwak, Min-Jung; Song, Ju Yeon; Kim, Byung Kwon; Chi, Won-Jae; Kwon, Soon-Kyeong; Choi, Soobeom; Chang, Yong-Keun; Hong, Soon-Kwang; Kim, Jihyun F.

    2012-01-01

    Here, we present the high-quality draft genome sequence of the agar-degrading marine gammaproteobacterium Alteromonadaceae sp. strain G7, which was isolated from coastal seawater to be utilized as a bioresource for production of agar-derived biofuels. The 3.91-Mb genome contains a number of genes encoding algal polysaccharide-degrading enzymes such as agarases and sulfatases.

  1. Growth and study of barium oxalate single crystals in agar gel

    Indian Academy of Sciences (India)

    Unknown

    In the present work, agar–agar gel (Brezina and Harvan- kova 1991; Agrawal et al 1999) was preferentially used for the growth of crystals by single and double diffusion tech- niques. A test tube having 25 cm in length and 2⋅5 cm in dia- meter was employed. In single diffusion, hot aqueous agar gel and oxalic acid solution ...

  2. Electrospinning of agar/PVA aqueous solutions and its relation with rheological properties.

    Science.gov (United States)

    Sousa, Ana M M; Souza, Hiléia K S; Uknalis, Joseph; Liu, Shih-Chuan; Gonçalves, Maria P; Liu, LinShu

    2015-01-22

    In this work, we report the successful fabrication of agar-based nanofibers by electrospinning technique, using water as solvent media. A tubeless spinneret was attached inside the electrospinning chamber, operating at 50°C, to avoid agar gelation. Agar pure solution (1 wt%) showed inadequate spinnability regardless of the used electrospinning conditions. The addition of a co-blending polymer such as PVA (10 wt% starting solution) improved the solutions viscoelasticity and hence, the solutions spinnability. Agar/PVA solutions were prepared with different mass ratios (100/0, 50/50, 40/60, 30/70, 20/80 and 0/100) and electrospun at various sets of electrospinning conditions. Best nanofibers were obtained with 30/70 and 20/80 agar/PVA blends while samples with higher agar contents (50/50 and 40/60 agar/PVA) were harder to process and led to discontinuous fibrous mats. This first set of encouraging results can open a new window of opportunities for agar-based biomaterials in the form of nanofibers. Published by Elsevier Ltd.

  3. Agar composition affects in vitro screening of biocontrol activity of antagonistic microorganisms

    NARCIS (Netherlands)

    Bosmans, Lien; De Bruijn, I.; de Mot, Rene; Readers, Hans; Lievens, Bart

    2016-01-01

    Agar-based screening assays are the method of choice when evaluating antagonistic potential of bacterial biocontrol-candidates against pathogens.Weshowed thatwhen using the samemedium, but different agar compositions, the activity of a bacterial antagonist against Agrobacteriumwas strongly affected.

  4. E. coli swimming over agar in a thin aqueous film

    Science.gov (United States)

    Berg, Howard

    2010-11-01

    When cells of Escherichia coli are grown in a rich medium over somewhat soft agar (0.45%) they elongate, produce more flagella, and swarm (or flock). Their behavior is dominated by collisions: an individual cell's velocity is randomized in about 0.2 s [1]. However, cells do not swim in spirals, as they do when in a thick layer of fluid near a solid boundary [2]. This suggests that the surface of the swarm is stationary, i.e., that the cells swim in a thin film of fluid between two fixed surfaces. We showed that this is the case by following the motion of MgO smoke particles deposited at the fluid-air interface [3]. By visualizing flagella of cells in swarms, we found that cells can escape from a confined environment by swimming back through the flagellar bundle, without changing the orientation of the cell body. This maneuver involves normal-to-curly and curly-to-normal polymorphic transformations [4]. These phenomena will be illustrated.[4pt] [1] Darnton NC, Turner L, Rojevsky S, & Berg HC (2010) Dynamics of bacterial swarming. Biophys. J. 98:2082-2090.[0pt] [2] Lauga E, DiLuzio WR, Whitesides GM, & Stone HA (2006) Swimming in circles: motion of bacteria near solid boundaries. Biophys. J. 90:400-412.[0pt] [3] Zhang R, Turner L, & Berg HC (2010) The upper surface of an Escherichia coli swarm is stationary. Proc. Natl. Acad. Sci. USA 107:288-290.[0pt] [4] Turner L, Zhang R, Darnton NC, & Berg HC (2010) Visualization of flagella during bacterial swarming. J. Bacteriol. 192:3259-3267.

  5. Fabrication and Optimization of a PAGATA Gel Dosimeter: Increasing the Melting Point of the PAGAT Gel Dosimeter with Agarose Additive

    Directory of Open Access Journals (Sweden)

    Bakhtiar Azadbakht

    2010-12-01

    Full Text Available Introduction: The PAGAT polymer gel dosimeter melts at 30 ˚C and even at room temperature during the summer, so it needs to be kept in a cool place such as a refrigerator. To increase the stability of the PAGAT gel, different amounts of agarose were added to the PAGAT gel composition and the PAGATA gel was manufactured. Material and Methods: The PAGATA gel vials were irradiated using a Co-60 machine. Then, the samples were evaluated using a 1.5 T Siemens MRI scanner. The ingredients of the PAGATA normoxic gel dosimeter were 4.5% N-N' methylen-bis-acrylamide, 4.5% acrylamide, 4.5% gelatine, 5 mM tetrakis (THPC, 0.01 mM hydroquinone (HQ, 0.5% agarose and 86% de-ionized water (HPLC. Results: Melting point and sensitivity of the PAGAT gel dosimeter with addition of 0.0, 0.3, 0.5, 1.0, 1.5 and 2.0% of agarose were measured, in which the melting points were increased to 30, 82, 86, 88, 89 and 90°C and their sensitivities found to be 0.113, 0.1059, 0.125, 0.122, 0.115 and 0.2  respectively. Discussion and Conclusions: Adding agarose increased the sensitivity and background R2 of the evaluated samples. The optimum amount of agarose was found to be 0.5% regarding these parameters and also the melting point of the gel dosimeter. A value of 0.5% agarose was found to be an optimum value considering the increase of sensitivity to 0.125 and melting point to 86°C but at the expense of increasing the background R2 to 4.530.

  6. Adsorptive removal of methylene blue by agar: effects of NaCl and ethanol

    Science.gov (United States)

    2012-01-01

    Adsorption of methylene blue (MB) on agar was investigated as a function of temperature (308-328 K), different concentrations of NaCl and HCl and various weight percentages of binary mixtures of ethanol with water. It was observed that the maximum experimental adsorption capacity, qm, exp, in water is up to 50 mg g-1 and decreases with increase in weight percentage of ethanol and NaCl and HCl concentration compared to that of water. Analysis of data using ARIAN model showed that MB adsorbs as monomer and dimer on the surface of agar. Binding constants of MB to agar were calculated using the Temkin isotherm. The process is exothermic in water and other solutions. The mean adsorption energy (E) value indicated binding of MB to agar is chemical adsorption. Kinetics of this interaction obeys from the pseudo-second-order model and diffusion of the MB molecules into the agar is the main rate-controlling step. PMID:22339759

  7. Characterization of the species Malassezia pachydermatis and re-evaluation of its lipid dependence using a synthetic agar medium.

    Science.gov (United States)

    Puig, Laura; Bragulat, M Rosa; Castellá, Gemma; Cabañes, F Javier

    2017-01-01

    The genus Malassezia includes lipophilic yeasts, which are part of the skin microbiota of various mammals and birds. Unlike the rest of Malassezia species, M. pachydermatis is described as non-lipid-dependent, as it is able to grow on Sabouraud glucose agar (SGA) without lipid supplementation. In this study we have examined the phenotypic variability within M. pachydermatis and confirmed its lipid-dependent nature using a synthetic agar medium. We used a selection of representative non-lipid-dependent strains from different animal species and three atypical lipid-dependent strains of this species, which were not able to grow after multiple passages on SGA. More than 400 lipid-dependent Malassezia isolates from animals were studied in order to detect the three lipid-dependent strains of M. pachydermatis. The identity of the atypical strains was confirmed by DNA sequencing. On the other hand, we have modified the Tween diffusion test, which is widely used in the characterization of these yeasts, by using a synthetic agar-based medium instead of SGA. This modification has proved to be useful for differentiation of M. pachydermatis strains, providing reproducible results and a straightforward interpretation. The finding of these peculiar lipid-dependent strains exemplifies the large variability within the species M. pachydermatis, which involves rare atypical strains with particular growth requirements.

  8. AGAR FROM MALAYSIAN RED SEAWEED AS POTENTIAL MATERIAL FOR SYNTHESIS OF BIOPLASTIC FILM

    Directory of Open Access Journals (Sweden)

    SIEW-LING HII

    2016-07-01

    Full Text Available The main aim of this study was to identify the potential use of agar extracted from red seaweed, Gracilaria salicornia, collected from the coastal area of Malaysia as the raw material for synthesis of bioplastic film. Agar was extracted via two extraction methods: (1 alkali extraction method and (2 photo bleaching extraction method. The yields of agar by both of the methods were 9 to 11 %. The alkali extracted agar (AEA and photo bleached agar (PBA were incorporated as the raw materials for the formation of bioplastic films while sago starch and glycerol were added to increase workability. Physicochemical properties of the two bioplastic films were characterised. FTIR analysis confirmed the presence of agar in both plastic films with the presence of 3,6- anhydrogalactose residues and further indicated that the interactions of agar and sago starch were strong in both PBA and AEA films. The results showed that tensile strength and percent elongation of PBA film (3.067 MPa, 3.270 % was higher than AEA film (2.431 MPa, 2.476 %. Thermogravimetric analysis (TGA; % residual weight revealed that AEA film has higher thermal stability (14.80 % than PBA film (10.27 % while rheological results proved that both films exhibited non-Newtonian behaviors. The AEA film was completely decomposed after 30 days in the soil burial test. Results of current study show a wide range of future possibilities and commercial applications of AEA and PBA bioplastic films.

  9. Isoenzyme patterns of pathogenic and non-pathogenic Naegleria spp. using agarose isoelectric focusing.

    Science.gov (United States)

    De Jonckheere, J F

    1982-01-01

    Using agarose isoelectric focusing, the isoenzyme patterns of 7 different enzymes were compared in 52 Naegleria strains. The pathogenic N. fowleri was found the most homogeneous species. N. lovaniensis seems to be constituted of different types which form nevertheless a cohesive group. Within N. gruberi, large interstrain band variations were found in almost all enzyme systems. A re-examination of the taxonomic position of this species may therefore be taken into consideration. High temperature strains from Australia were confirmed to be different from N. lovaniensis. Members of a new pathogenic Naegleria sp., N. australiensis, seem to occur in Europe. Large thermophilic strains with many large pores in the cysts show identical zymograms and may constitute a new species or genus.

  10. Analysis of Replicating Mitochondrial DNA by In Organello Labeling and Two-Dimensional Agarose Gel Electrophoresis.

    Science.gov (United States)

    Holt, Ian J; Kazak, Lawrence; Reyes, Aurelio; Wood, Stuart R

    2016-01-01

    Our understanding of the mechanisms of DNA replication in a broad range of organisms and viruses has benefited from the application of two-dimensional agarose gel electrophoresis (2D-AGE). The method resolves DNA molecules on the basis of size and shape and is technically straightforward. 2D-AGE sparked controversy in the field of mitochondria when it revealed replicating molecules with lengthy tracts of RNA, a phenomenon never before reported in nature. More recently, radioisotope labeling of the DNA in the mitochondria has been coupled with 2D-AGE. In its first application, this procedure helped to delineate the "bootlace mechanism of mitochondrial DNA replication," in which processed mitochondrial transcripts are hybridized to the lagging strand template at the replication fork as the leading DNA strand is synthesized. This chapter provides details of the method, how it has been applied to date and concludes with some potential future applications of the technique.

  11. Fractionation of SWNT/nucleic acid complexes by agarose gel electrophoresis

    Science.gov (United States)

    Vetcher, Alexandre A.; Srinivasan, Srimeenakshi; Vetcher, Ivan A.; Abramov, Semen M.; Kozlov, Mikhail; Baughman, Ray H.; Levene, Stephen D.

    2006-08-01

    We show that aqueous dispersions of single-walled carbon nanotubes (SWNTs), prepared with the aid of nucleic acids (NAs) such as RNA or DNA, can be separated into fractions using agarose gel electrophoresis. In a DC electric field, SWNT/NA complexes migrate in the gel in the direction of positive potential to form well-defined bands. Raman spectroscopy as a function of band position shows that nanotubes having different spectroscopic properties possess different electrophoretic mobilities. The migration patterns for SWNT/RNA and SWNT/DNA complexes differ. Parallel elution of the SWNT/NA complexes from the gel during electrophoresis and subsequent characterization by AFM reveals differences in nanotube diameter, length and curvature. The results suggest that fractionation of nanotubes can be achieved by this procedure. We discuss factors affecting the mobility of the nanotube complexes and propose analytical applications of this technique.

  12. Kinetic model for whey protein hydrolysis by alcalase multipoint-immobilized on agarose gel particles

    Directory of Open Access Journals (Sweden)

    R. Sousa Jr

    2004-06-01

    Full Text Available Partial hydrolysis of whey proteins by enzymes immobilized on an inert support can either change or evidence functional properties of the produced peptides, thereby increasing their applications. The hydrolysis of sweet cheese whey proteins by alcalase, which is multipoint-immobilized on agarose gel, is studied here. A Michaelis-Menten model that takes into account competitive inhibition by the product was fitted to experimental data. The influence of pH on the kinetic parameters in the range 6.0 to 11.0 was assessed, at 50ºC. Initial reaction-rate assays in a pHstat at different concentrations of substrate were used to estimate kinetic and Michaelis-Menten parameters, k and K M. Experimental data from long-term batch assays were used to quantify the inhibition parameter, K I. The fitting of the model to the experimental data was accurate in the entire pH range.

  13. Candida krusei form mycelia along agar surfaces towards each other and other Candida species.

    Science.gov (United States)

    Fleischmann, Jacob; Broeckling, Corey D; Lyons, Sarah

    2017-03-11

    Candida krusei has been known to exhibit communal interactions such as pellicle formation and crawling out of nutritional broth. We noticed another possible interaction on agar surfaces, where C. krusei yeast cells formed mycelia along agar surfaces toward each other. We report here the results of experiments to study this interaction. When C.krusei yeast cells are plated in parallel streaks, they form mycelia along agar surfaces toward other yeasts. They also detect the presence of Candida albicans and Candida glabrata across agar surfaces, while the latter two react neither to their own kind, nor to C. krusei. Secreted molecule(s) are likely involved as C.krusei does not react to heat killed C. krusei. Timing and rate of mycelia formation across distances suggests that mycelia start forming when a secreted molecule(s) on agar surface reaches a certain concentration. We detected farnesol, tyrosol and tryptophol molecules that may be involved with mycelial formation, on the agar surfaces between yeast streaks. Unexpectedly the amounts detected between streaks were significantly higher than would have expected from additive amounts of two streaks. All three Candida species secreted these molecules. When tested on agar surface however, none of these molecules individually or combined induced mycelia formation by C. krusei. Our data confirms another communal interaction by C. krusei, manifested by formation of mycelia by yeast cells toward their own kind and other yeasts on agar surfaces. We detected secretion of farnesol, tyrosol and tryptophol by C. krusei but none of these molecules induced this activity on agar surface making it unlikely that they are the ones utilized by this yeast for this activity.

  14. Comparative assessment of intrinsic mechanical stimuli on knee cartilage and compressed agarose constructs.

    Science.gov (United States)

    Completo, A; Bandeiras, C; Fonseca, F

    2017-06-01

    A well-established cue for improving the properties of tissue-engineered cartilage is mechanical stimulation. However, the explicit ranges of mechanical stimuli that correspond to favorable metabolic outcomes are elusive. Usually, these outcomes have only been associated with the applied strain and frequency, an oversimplification that can hide the fundamental relationship between the intrinsic mechanical stimuli and the metabolic outcomes. This highlights two important key issues: the firstly is related to the evaluation of the intrinsic mechanical stimuli of native cartilage; the second, assuming that the intrinsic mechanical stimuli will be important, deals with the ability to replicate them on the tissue-engineered constructs. This study quantifies and compares the volume of cartilage and agarose subjected to a given magnitude range of each intrinsic mechanical stimulus, through a numerical simulation of a patient-specific knee model coupled with experimental data of contact during the stance phase of gait, and agarose constructs under direct-dynamic compression. The results suggest that direct compression loading needs to be parameterized with time-dependence during the initial culture period in order to better reproduce each one of the intrinsic mechanical stimuli developed in the patient-specific cartilage. A loading regime which combines time periods of low compressive strain (5%) and frequency (0.5Hz), in order to approach the maximal principal strain and fluid velocity stimulus of the patient-specific cartilage, with time periods of high compressive strain (20%) and frequency (3Hz), in order to approach the pore pressure values, may be advantageous relatively to a single loading regime throughout the full culture period. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  15. Purification of CD47-streptavidin fusion protein from bacterial lysate using biotin-agarose affinity chromatography.

    Science.gov (United States)

    Salehi, Nasrin; Peng, Ching-An

    2016-07-08

    CD47 is a widely expressed transmembrane glycoprotein that modulates the activity of a plethora of immune cells via its extracellular domain. Therefore, CD47 plays important roles in the regulation of immune responses and may serve as targets for the development of immunotherapeutic agents. To make sure CD47 functionality is intact under the process of protein conjugation, CD47-streptavidin fusion protein was expressed and purified because it can easily bind to biotin-tagged materials via the unique biotin-streptavidin affinity. In this study, gene sequences of CD47 extracellular domain (CD47ECD) and core streptavidin (coreSA) with a total 834 bp were inserted into pET20b plasmid to construct recombinant plasmid encoding CD47-SA fusion gene. After bacteria transformation, the CD47-SA fusion protein was expressed by isopropyl-β-d-thiogalactopyranoside (IPTG) induction. The collected bacteria lysate was loaded on biotinylated agarose to proceed the purification of CD47-SA fusion protein. Due to the unexpected high affinity between biotin and coreSA, standard washing and elution approaches (e.g., varying pH, using biotin, and applying guanidine hydrochloride) reported for biotin-streptavidin affinity chromatography were not able to separate the target fusion protein. Instead, using low concentration of the non-ionic detergent Triton X-100 followed with alkaline buffer could efficiently weaken the binding between biotin and coreSA, thereby eluting out CD47-SA fusion protein from the biotin agarose column. The purified CD47-SA fusion protein was further characterized by molecular biology methods and its antiphagocytic functionality was confirmed by the phagocytosis assay. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:949-958, 2016. © 2016 American Institute of Chemical Engineers.

  16. Degradation of RNA during lysis of Escherichia coli cells in agarose plugs breaks the chromosome.

    Directory of Open Access Journals (Sweden)

    Sharik R Khan

    Full Text Available The nucleoid of Escherichia coli comprises DNA, nucleoid associated proteins (NAPs and RNA, whose role is unclear. We found that lysing bacterial cells embedded in agarose plugs in the presence of RNases caused massive fragmentation of the chromosomal DNA. This RNase-induced chromosomal fragmentation (RiCF was completely dependent on the presence of RNase around lysing cells, while the maximal chromosomal breakage required fast cell lysis. Cell lysis in plugs without RNAse made the chromosomal DNA resistant to subsequent RNAse treatment. RiCF was not influenced by changes in the DNA supercoiling, but was influenced by growth temperature or age of the culture. RiCF was partially dependent on H-NS, histone-like nucleoid structuring- and global transcription regulator protein. The hupAB deletion of heat-unstable nucleoid protein (HU caused increase in spontaneous fragmentation that was further increased when combined with deletions in two non-coding RNAs, nc1 and nc5. RiCF was completely dependent upon endonuclease I, a periplasmic deoxyribonuclease that is normally found inhibited by cellular RNA. Unlike RiCF, the spontaneous fragmentation in hupAB nc1 nc5 quadruple mutant was resistant to deletion of endonuclease I. RiCF-like phenomenon was observed without addition of RNase to agarose plugs if EDTA was significantly reduced during cell lysis. Addition of RNase under this condition was synergistic, breaking chromosomes into pieces too small to be retained by the pulsed field gels. RNase-independent fragmentation was qualitatively and quantitatively comparable to RiCF and was partially mediated by endonuclease I.

  17. Photothermal Microneedle Etching: Improved Three-Dimensional Microfabrication Method for Agarose Gel for Topographical Control of Cultured Cell Communities

    Science.gov (United States)

    Moriguchi, Hiroyuki; Yasuda, Kenji

    2006-08-01

    We have developed a new three-dimensional (3D) microfabrication method for agarose gel, photothermal microneedle etching (PTMNE), by means of an improved photothermal spot heating using a focused 1064 nm laser beam for melting a portion of the agarose layer at the tip of the microneedle, where a photoabsorbent chromium layer is coated to be heated. The advantage of this method is that it allows the 3D control of the melting topography within the thick agarose layer with a 2 μm resolution, whereas conventional photothermal etching can enable only two-dimensional (2D) control on the surface of the chip. By this method, we can form the spheroid clusters of particular cells from isolated single cells without any physical contact with other cells in other chambers, which is important for measuring the community effect of the cell group from isolated single cells. When we set single cancer cells in microchambers of 100 μm in diameter, formed in a 50-μm-thick agarose layer, we observed that they grew, divided, and formed spheroid clusters of cells in each microchamber. The result indicates the potential of this method to be a fundamental technique in the research of multicellular spherical clusters of cells for checking the community effect of cells in 3D structures, such as the permeabilities of chemicals and substrates into the cluster, which is complementary to conventional 2D dish cultivation and can contribute to the cell-based screening of drugs.

  18. Specific capture, recovery and culture of cancer cells using oriented antibody-modified polystyrene chips coated with agarose film.

    Science.gov (United States)

    Jeong, Jiyun; Lee, Yeolin; Yoo, Yeongeun; Lee, Myung Kyu

    2018-02-01

    Agarose gel can be used for three dimensional (3D) cell culture because it prevents cell attachment. The dried agarose film coated on a culture plate also protected cell attachment and allowed 3D growth of cancer cells. We developed an efficient method for agarose film coating on an oxygen-plasma treated micropost polystyrene chip prepared by an injection molding process. The agarose film was modified to maleimide or Ni-NTA groups for covalent or cleavable attachment of photoactivatable Fc-specific antibody binding proteins (PFcBPs) via their N-terminal cysteine residues or 6xHis tag, respectively. The antibodies photocrosslinked onto the PFcBP-modified chips specifically captured the target cells without nonspecific binding, and the captured cells grew 3D modes on the chips. The captured cells on the cleavable antibody-modified chips were easily recovered by treatment of commercial trypsin-EDTA solution. Under fluidic conditions using an antibody-modified micropost chip, the cells were mainly captured on the micropost walls of the chip rather than on the bottom of it. The presented method will also be applicable for immobilization of oriented antibodies on various microfluidic chips with different structures. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. No Evidence of Viral Transmission following Long-Term Implantation of Agarose Encapsulated Porcine Islets in Diabetic Dogs

    Directory of Open Access Journals (Sweden)

    Lawrence S. Gazda

    2014-01-01

    Full Text Available We have previously described the use of a double coated agarose-agarose porcine islet macrobead for the treatment of type I diabetes mellitus. In the current study, the long-term viral safety of macrobead implantation into pancreatectomized diabetic dogs treated with pravastatin (n=3 was assessed while 2 dogs served as nonimplanted controls. A more gradual return to preimplant insulin requirements occurred after a 2nd implant procedure (days 148, 189, and >652 when compared to a first macrobead implantation (days 9, 21, and 21 in all macrobead implanted animals. In all three implanted dogs, porcine C-peptide was detected in the blood for at least 10 days following the first implant and for at least 26 days following the second implant. C-peptide was also present in the peritoneal fluid of all three implanted dogs at 6 months after 2nd implant and in 2 of 3 dogs at necropsy. Prescreening results of islet macrobeads and culture media prior to transplantation were negative for 13 viruses. No evidence of PERV or other viral transmission was found throughout the study. This study demonstrates that the long-term (2.4 years implantation of agarose-agarose encapsulated porcine islets is a safe procedure in a large animal model of type I diabetes mellitus.

  20. Tuning mechanical performance of poly(ethylene glycol) and agarose interpenetrating network hydrogels for cartilage tissue engineering.

    Science.gov (United States)

    Rennerfeldt, Deena A; Renth, Amanda N; Talata, Zsolt; Gehrke, Stevin H; Detamore, Michael S

    2013-11-01

    Hydrogels are attractive for tissue engineering applications due to their incredible versatility, but they can be limited in cartilage tissue engineering applications due to inadequate mechanical performance. In an effort to address this limitation, our team previously reported the drastic improvement in the mechanical performance of interpenetrating networks (IPNs) of poly(ethylene glycol) diacrylate (PEG-DA) and agarose relative to pure PEG-DA and agarose networks. The goal of the current study was specifically to determine the relative importance of PEG-DA concentration, agarose concentration, and PEG-DA molecular weight in controlling mechanical performance, swelling characteristics, and network parameters. IPNs consistently had compressive and shear moduli greater than the additive sum of either single network when compared to pure PEG-DA gels with a similar PEG-DA content. IPNs withstood a maximum stress of up to 4.0 MPa in unconfined compression, with increased PEG-DA molecular weight being the greatest contributing factor to improved failure properties. However, aside from failure properties, PEG-DA concentration was the most influential factor for the large majority of properties. Increasing the agarose and PEG-DA concentrations as well as the PEG-DA molecular weight of agarose/PEG-DA IPNs and pure PEG-DA gels improved moduli and maximum stresses by as much as an order of magnitude or greater compared to pure PEG-DA gels in our previous studies. Although the viability of encapsulated chondrocytes was not significantly affected by IPN formulation, glycosaminoglycan (GAG) content was significantly influenced, with a 12-fold increase over a three-week period in gels with a lower PEG-DA concentration. These results suggest that mechanical performance of IPNs may be tuned with partial but not complete independence from biological performance of encapsulated cells. © 2013 Elsevier Ltd. All rights reserved.

  1. A fresh liver agar substrate for rearing small numbers of forensically important blow flies (Diptera: Calliphoridae)

    Science.gov (United States)

    Gruner, Susan V.; Slone, Daniel H.

    2014-01-01

    Forensically important calliphorids can be reared on a mixture of beef liver and agar. Small pieces of meat, especially fresh or frozen beef liver, will desiccate in 2–6 h, but this simple-to-make feeding substrate remains moist for at least 12 h at 25 and 30°C without desiccation, even in small (5 g) amounts. We determined the survivorship of small numbers of Chrysomya megacephala (F.) (first-instar larvae to adult eclosion) raised on 5 g of liver agar and fresh beef liver. We found that all larvae raised on 5 g of liver died due to desiccation, but survivorship on 5 g of liver agar was equivalent to that on larger (50 g) pieces of either liver agar or beef liver.

  2. Low density, microcellular, dopable, agar/gelatin foams for pulsed power experiments

    Energy Technology Data Exchange (ETDEWEB)

    McNamara, W.F. [Orion International Technologies, Inc., Albuquerque, NM (United States); Aubert, J.H. [Sandia National Lab., Albuquerque, NM (United States)

    1997-04-01

    Low-density, microcellular foams prepared from the natural polymers agar and gelatin have been developed for pulsed-power physics experiments. Numerous experiments were supported with foams having densities at or below 10 mg/cm{sup 3}. For some of the experiments, the agar/gelatin foam was uniformly doped with metallic elements using soluble salts. Depending on the method of preparation, cell sizes were typically below 10 microns and for one process were below 1.0 micron.

  3. Immediate differentiation of salmonella-resembling colonies on brilliant green agar

    DEFF Research Database (Denmark)

    Jensen, Annette Nygaard; Hoorfar, Jeffrey

    2000-01-01

    A rapid biochemical system (OBIS) based on immediate enzymatic differentiation of Citrobacter, Proteus, Providencia, Hafnia and Morganella spp. from Salmonella on brilliant green agar was evaluated A total of 96 field isolates from various Salmonella serotypes, 18 Citrobacter freundii and 25...... isolates of other Enterobacteriaceae were tested All Salmonella isolates were identified correctly by the kit, and none of the Enterobacteriaceae isolates were identified as Salmonella. The results indicate complete specificity for Salmonella colonies on brilliant green agar....

  4. Precipitate produced by Serratia marcescens on MacConkey agar: useful diagnostic test.

    Science.gov (United States)

    Black, W A

    1978-11-01

    The production of a precipitate by Serratia marcescens on Oxoid MacConkey agar has proven useful as a laboratory diagnostic test. This phenomenon is specific for Serratia within the Enterobacteriaceae, although precipitate production is also given by Acinetobacter anitratus and some Pseudomonas, Alcaligenes, and Aeromonas species. Precipitate production seems to be specific for certain batches of MacConkey agar, and is probably related to a specific property of some batches of bile salts.

  5. A radiobiological comparison of human tumor soft-agar clonogenic assays.

    Science.gov (United States)

    West, C M; Sutherland, R M

    1986-06-15

    Radiation survival curves have been generated for 3 human tumor cell lines as a means of comparing and evaluating the validity of human tumor soft-agar clonogenic assays. The assays investigated were the Hamburger-Salmon, Courtenay-Mills, Courtenay-Mills plus additions, soft agar (no additions), and soft agar plus additions. The additions were formulated to supplement the media used in soft agar assays of primary ovarian and cervical carcinoma specimens. Supplementing the media with additions led to a 2- to 3-fold increase in PE of CaSki cells but had no effect on the PEs of ME180 and OWI cells. Radiation survival curves were similar in all assays for CaSki and OWI but differed for ME180 cells. For ME180 cells, the Courtenay-Mills and soft agar assays plus additions produced the most radioresistant curves (Do = 2.2 Gy); the cells were more responsive when assayed by the Hamburger-Salmon method (Do = 1.5 Gy), and the soft agar and Courtenay-Mills assays gave the most radiosensitive curves (Do = 1.2 Gy). These results demonstrate that the PE of human tumor cell lines may be increased with no effect on radiation survival; radiation survival may be altered without changes in PE and neither may be altered by applying modifications and supplements to existing clonogenic assays.

  6. A hidden pitfall in the preparation of agar media undermines microorganism cultivability.

    Science.gov (United States)

    Tanaka, Tomohiro; Kawasaki, Kosei; Daimon, Serina; Kitagawa, Wataru; Yamamoto, Kyosuke; Tamaki, Hideyuki; Tanaka, Michiko; Nakatsu, Cindy H; Kamagata, Yoichi

    2014-12-01

    Microbiologists have been using agar growth medium for over 120 years. It revolutionized microbiology in the 1890s when microbiologists were seeking effective methods to isolate microorganisms, which led to the successful cultivation of microorganisms as single clones. But there has been a disparity between total cell counts and cultivable cell counts on plates, often referred to as the "great plate count anomaly," that has long been a phenomenon that still remains unsolved. Here, we report that a common practice microbiologists have employed to prepare agar medium has a hidden pitfall: when phosphate was autoclaved together with agar to prepare solid growth media (PT medium), total colony counts were remarkably lower than those grown on agar plates in which phosphate and agar were separately autoclaved and mixed right before solidification (PS medium). We used a pure culture of Gemmatimonas aurantiaca T-27(T) and three representative sources of environmental samples, soil, sediment, and water, as inocula and compared colony counts between PT and PS agar plates. There were higher numbers of CFU on PS medium than on PT medium using G. aurantiaca or any of the environmental samples. Chemical analysis of PT agar plates suggested that hydrogen peroxide was contributing to growth inhibition. Comparison of 454 pyrosequences of the environmental samples to the isolates revealed that taxa grown on PS medium were more reflective of the original community structure than those grown on PT medium. Moreover, more hitherto-uncultivated microbes grew on PS than on PT medium. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  7. Comparison of selective agars recommended by method ISO 11290-1 and chromogenic agars for the isolation of Listeria sp. in refrigerated sausages

    Directory of Open Access Journals (Sweden)

    Thalyta Marina Benetti

    2012-12-01

    Full Text Available The aim of this study was to determine the prevalence of Listeria sp. in refrigerated sausages, and to compare the performance of the selective plating media employed in the ISO 11290-1 method (PALCAM and Oxford agars with chromogenic agars (Chromogenic Listeria agars CM 1080 (OCLA and CM 1084. The prevalence of Listeria sp. detected was 52.9%, comprising 13.7% L. monocytogenes strains. The efficacy of the four agars for the isolation of L. monocytogenes proved to be satisfactory. Despite differences in composition of the chromogenic media assessed, these disparities did not affect concordance among results. However, PALCAM agar was shown to suppress other microorganisms more effectively, being more applicable for detecting Listeria strains present in lower quantities. Based on these results, the use of PALCAM agar, in combination with a chromogenic media, is recommended for enhanced isolation of atypical Listeria sp. strains in meat products.Este estudo teve como objetivo a análise da prevalência de Listeria sp. em linguiças resfriadas e a comparação dos meios seletivos utilizados no plaqueamento do método ISO 11290-1 (Ágar PALCAM e Ágar Oxford, e ágares cromogênicos (Ágares Listeria Cromogênico CM 1080 (OCLA e CM 1084 (ISO. A frequência de Listeria sp. foi de 52,9%, sendo que destas, 13,7% corresponderam à L. monocytogenes. A eficácia dos quatro ágares para o isolamento de L. monocytogenes demonstrou-se satisfatória. Apesar de haver algumas diferenças nas composições dos meios cromogênicos analisados, estas não pareceram influenciar nas concordâncias entre os resultados expressos. Contudo, o ágar PALCAM mostrou-se mais eficaz na supressão de outros micro-organismos, aumentando, assim, a possibilidade de detecção de espécies de Listeria presentes em número reduzido. Através deste trabalho sugere-se a utilização do ágar PALCAM associado a um meio cromogênico para aumentar a chance de isolamento de cepas at

  8. Stabilization of Candida antarctica Lipase B (CALB Immobilized on Octyl Agarose by Treatment with Polyethyleneimine (PEI

    Directory of Open Access Journals (Sweden)

    Sara Peirce

    2016-06-01

    Full Text Available Lipase B from Candida antarctica (CALB was immobilized on octyl agarose (OC and physically modified with polyethyleneimine (PEI in order to confer a strong ion exchange character to the enzyme and thus enable the immobilization of other enzymes on its surface. The enzyme activity was fully maintained during the coating and the thermal stability was marginally improved. The enzyme release from the support by incubation in the non-ionic detergent Triton X-100 was more difficult after the PEI-coating, suggesting that some intermolecular physical crosslinking had occurred, making this desorption more difficult. Thermal stability was marginally improved, but the stability of the OCCALB-PEI was significantly better than that of OCCALB during inactivation in mixtures of aqueous buffer and organic cosolvents. SDS-PAGE analysis of the inactivated biocatalyst showed the OCCALB released some enzyme to the medium during inactivation, and this was partially prevented by coating with PEI. This effect was obtained without preventing the possibility of reuse of the support by incubation in 2% ionic detergents. That way, this modified CALB not only has a strong anion exchange nature, while maintaining the activity, but it also shows improved stability under diverse reaction conditions without affecting the reversibility of the immobilization.

  9. Upregulation of matrix synthesis in chondrocyte-seeded agarose following sustained bi-axial cyclic loading

    Directory of Open Access Journals (Sweden)

    Belinda Pingguan-Murphy

    2012-08-01

    Full Text Available OBJECTIVES: The promotion of extracellular matrix synthesis by chondrocytes is a requisite part of an effective cartilage tissue engineering strategy. The aim of this in vitro study was to determine the effect of bi-axial cyclic mechanical loading on cell proliferation and the synthesis of glycosaminoglycans by chondrocytes in threedimensional cultures. METHOD: A strain comprising 10% direct compression and 1% compressive shear was applied to bovine chondrocytes seeded in an agarose gel during two 12-hour conditioning periods separated by a 12-hour resting period. RESULTS: The bi-axial-loaded chondrocytes demonstrated a significant increase in glycosaminoglycan synthesis compared with samples exposed to uni-axial or no loading over the same period (p<0.05. The use of a free-swelling recovery period prior to the loading regime resulted in additional glycosaminoglycan production and a significant increase in DNA content (p<0.05, indicating cell proliferation. CONCLUSIONS: These results demonstrate that the use of a bi-axial loading regime results in increased matrix production compared with uni-axial loading.

  10. Mechanically tailored agarose hydrogels through molecular alloying with β-sheet polysaccharides.

    Science.gov (United States)

    Forget, Aurelien; Pique, Raphaelle-Anne; Ahmadi, Vincent; Lüdeke, Steffen; Shastri, V Prasad

    2015-01-01

    There is mounting evidence that the mechanical property of tissues provides important cues that control cell fate. However, implementation of hydrogels with tunable physicochemical properties is limited due to the challenges associated with crosslinking chemistries. It has been recently shown that mechanically well-defined injectable polysaccharide hydrogels can be engineered by switching their secondary structure from an α-helix to a β-sheet. Based on these findings, a new concept is presented to tailor the mechanical properties of agarose hydrogels via the blending with the β-sheet-rich carboxylated derivative. Using this simple strategy, gels with predictable roughness, fiber organization, and shear modulus ranging from 0.1 to 100 kPa can be formulated. Hydrogels whose mechanical properties can be precisely tailored in vivo without the recourse for chemical reactions are expected to play an important role in implementing mechanobiology paradigms in de novo tissue engineering. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Photoinduced Oxidative DNA Damage Revealed by an Agarose Gel Nicking Assay: A Biophysical Chemistry Laboratory Experiment

    Science.gov (United States)

    Shafirovich, Vladimir; Singh, Carolyn; Geacintov, Nicholas E.

    2003-11-01

    Oxidative damage of DNA molecules associated with electron-transfer reactions is an important phenomenon in living cells, which can lead to mutations and contribute to carcinogenesis and the aging processes. This article describes the design of several simple experiments to explore DNA damage initiated by photoinduced electron-transfer reactions sensitized by the acridine derivative, proflavine (PF). A supercoiled DNA agarose gel nicking assay is employed as a sensitive probe of DNA strand cleavage. A low-cost experimental and computer-interfaced imaging apparatus is described allowing for the digital recording and analysis of the gel electrophoresis results. The first experiment describes the formation of direct strand breaks in double-stranded DNA induced by photoexcitation of the intercalated PF molecules. The second experiment demonstrates that the addition of the well-known electron acceptor, methylviologen, gives rise to a significant enhancement of the photochemical DNA strand cleavage effect. This occurs by an electron transfer step to methylviologen that renders the inital photoinduced charge separation between photoexcited PF and DNA irreversible. The third experiment demonstrates that the action spectrum of the DNA photocleavage matches the absorption spectrum of DNA-bound, intercalated PF molecules, which differs from that of free PF molecules. This result demonstrates that the photoinduced DNA strand cleavage is initiated by intercalated rather than free PF molecules.

  12. Screening for amyloid aggregation by Semi-Denaturing Detergent-Agarose Gel Electrophoresis.

    Science.gov (United States)

    Halfmann, Randal; Lindquist, Susan

    2008-07-16

    Amyloid aggregation is associated with numerous protein misfolding pathologies and underlies the infectious properties of prions, which are conformationally self-templating proteins that are thought to have beneficial roles in lower organisms. Amyloids have been notoriously difficult to study due to their insolubility and structural heterogeneity. However, resolution of amyloid polymers based on size and detergent insolubility has been made possible by Semi-Denaturing Detergent-Agarose Gel Electrophoresis (SDD-AGE). This technique is finding widespread use for the detection and characterization of amyloid conformational variants. Here, we demonstrate an adaptation of this technique that facilitates its use in large-scale applications, such as screens for novel prions and other amyloidogenic proteins. The new SDD-AGE method uses capillary transfer for greater reliability and ease of use, and allows any sized gel to be accomodated. Thus, a large number of samples, prepared from cells or purified proteins, can be processed simultaneously for the presence of SDS-insoluble conformers of tagged proteins.

  13. Agarose gel electrophoresis reveals structural fluidity of a phage T3 DNA packaging intermediate.

    Science.gov (United States)

    Serwer, Philip; Wright, Elena T

    2012-01-01

    We find a new aspect of DNA packaging-associated structural fluidity for phage T3 capsids. The procedure is (i) glutaraldehyde cross-linking of in vivo DNA packaging intermediates for the stabilization of structure and then (ii) determining effective radius by two-dimensional agarose gel electrophoresis (2D-AGE). The intermediates are capsids with incompletely packaged DNA (ipDNA) and without an external DNA segment; these intermediates are called ipDNA-capsids. We initially increase the production of ipDNA-capsids by raising NaCl concentration during in vivo DNA packaging. By 2D-AGE, we find a new state of contracted shell for some particles of one previously identified ipDNA-capsid. The contracted shell-state is found when the ipDNA length/mature DNA length (F) is above 0.17, but not at lower F. Some contracted-shell ipDNA-capsids have the phage tail; others do not. The contracted-shell ipDNA-capsids are explained by premature DNA maturation cleavage that makes accessible a contracted-shell intermediate of a cycle of the T3 DNA packaging motor. The analysis of ipDNA-capsids, rather than intermediates with uncleaved DNA, provides a simplifying strategy for a complete biochemical analysis of in vivo DNA packaging. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. High resolution melt analysis (HRMA; a viable alternative to agarose gel electrophoresis for mouse genotyping.

    Directory of Open Access Journals (Sweden)

    Nicole Thomsen

    Full Text Available Most mouse genetics laboratories maintain mouse strains that require genotyping in order to identify the genetically modified animals. The plethora of mutagenesis strategies and publicly available mouse alleles means that any one laboratory may maintain alleles with random or targeted insertions of orthologous or unrelated sequences as well as random or targeted deletions and point mutants. Many experiments require that different strains be cross bred conferring the need to genotype progeny at more than one locus. In contrast to the range of new technologies for mouse mutagenesis, genotyping methods have remained relatively static with alleles typically discriminated by agarose gel electrophoresis of PCR products. This requires a large amount of researcher time. Additionally it is susceptible to contamination of future genotyping experiments because it requires that tubes containing PCR products be opened for analysis. Progress has been made with the genotyping of mouse point mutants because a range of new high-throughput techniques have been developed for the detection of Single Nucleotide Polymorphisms. Some of these techniques are suitable for genotyping point mutants but do not detect insertion or deletion alleles. Ideally, mouse genetics laboratories would use a single, high-throughput platform that enables closed-tube analysis to genotype the entire range of possible insertion and deletion alleles and point mutants. Here we show that High Resolution Melt Analysis meets these criteria, it is suitable for closed-tube genotyping of all allele types and current genotyping assays can be converted to this technology with little or no effort.

  15. Agarose gel electrophoresis and polyacrylamide gel electrophoresis for visualization of simple sequence repeats.

    Science.gov (United States)

    Anderson, James; Wright, Drew; Meksem, Khalid

    2013-01-01

    In the modern age of genetic research there is a constant search for ways to improve the efficiency of plant selection. The most recent technology that can result in a highly efficient means of selection and still be done at a low cost is through plant selection directed by simple sequence repeats (SSRs or microsatellites). The molecular markers are used to select for certain desirable plant traits without relying on ambiguous phenotypic data. The best way to detect these is the use of gel electrophoresis. Gel electrophoresis is a common technique in laboratory settings which is used to separate deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) by size. Loading DNA and RNA onto gels allows for visualization of the size of fragments through the separation of DNA and RNA fragments. This is achieved through the use of the charge in the particles. As the fragments separate, they form into distinct bands at set sizes. We describe the ability to visualize SSRs on slab gels of agarose and polyacrylamide gel electrophoresis.

  16. Performance comparison of capillary and agarose gel electrophoresis for the identification and characterization of monoclonal immunoglobulins.

    Science.gov (United States)

    McCudden, Christopher R; Mathews, Stephanie P; Hainsworth, Shirley A; Chapman, John F; Hammett-Stabler, Catherine A; Willis, Monte S; Grenache, David G

    2008-03-01

    The objective of this study was to compare gel- and capillary-based serum protein electrophoresis methods to identify and characterize monoclonal immunoglobulins (M proteins). Five reviewers interpreted 149 consecutively ordered serum specimens following agarose gel electrophoresis (AGE), capillary electrophoresis (CE), immunofixation electrophoresis (IFE), and subtraction immunotyping (IT). As a screening test for detecting M proteins, AGE and CE displayed similar sensitivity (91% and 92%, respectively). CE was less specific (74%) than AGE (81%). An analysis of interinterpreter agreement revealed that interpretations were more consistent using gel-based methods than capillary-based methods, with 80% of the gel interpretations being in complete (5/5) agreement compared with 67% of the capillary interpretations. After implementing the capillary-based methods, the number of tests per reportable result increased (from 1.58 to 1.73). CE is an analytically suitable alternative to AGE, but laboratories implementing it will need to continue IFE testing to characterize all M proteins detected by CE.

  17. DNA agarose gel electrophoresis for antioxidant analysis: Development of a quantitative approach for phenolic extracts.

    Science.gov (United States)

    Silva, Sara; Costa, Eduardo M; Vicente, Sandra; Veiga, Mariana; Calhau, Conceição; Morais, Rui M; Pintado, Manuela E

    2017-10-15

    Most of the fast in vitro assays proposed to determine the antioxidant capacity of a compound/extract lack either biological context or employ complex protocols. Therefore, the present work proposes the improvement of an agarose gel DNA electrophoresis in order to allow for a quantitative estimation of the antioxidant capacity of pure phenolic compounds as well as of a phenolic rich extract, while also considering their possible pro-oxidant effects. The result obtained demonstrated that the proposed method allowed for the evaluation of the protection of DNA oxidation [in the presence of hydrogen peroxide (H 2 O 2 ) and an H 2 O 2 /iron (III) chloride (FeCl 3 ) systems] as well as for the observation of pro-oxidant activities, with the measurements registering interclass correlation coefficients above 0.9. Moreover, this method allowed for the characterization of the antioxidant capacity of a blueberry extract while demonstrating that it had no perceived pro-oxidant effect. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Preparation of colloidal gold-labeled agarose-gelatin microspherules for electron microscopic studies of phagocytosis in cultured cells.

    Science.gov (United States)

    Gao, K X; Huang, L

    1987-02-01

    Agarose-gelatin microspherules about 0.5 micron or larger are prepared with emulsification of 4% agarose-gelatin sol containing 0.2 M N-octylglucoside in an organic phase composed of cyclohexane, egg lecithin, Span 80, and ethanol, followed by extraction of lipophilic components with cyclohexane and ether. Colloidal gold particles are then introduced into microspherules using gold chloride reacting at room temperature with tannic acid in a specified concentration range. After they have been coated with bovine serum albumin or mouse IgG, colloidal gold-labeled microspherules can be readily phagocytized by mouse L-cells and P388 cells after incubation for several hours. In addition to their use as a novel marker for phagocytosis, we discuss other potential uses for these colloidal gold-labeled microspherules.

  19. Theoretical and experimental NMR studies on muscimol from fly agaric mushroom (Amanita muscaria)

    Science.gov (United States)

    Kupka, Teobald; Wieczorek, Piotr P.

    2016-01-01

    In this article we report results of combined theoretical and experimental NMR studies on muscimol, the bioactive alkaloid from fly agaric mushroom (Amanita muscaria). The assignment of 1H and 13C NMR spectra of muscimol in DMSO-d6 was supported by additional two-dimensional heteronuclear correlated spectra (2D NMR) and gauge independent atomic orbital (GIAO) NMR calculations using density functional theory (DFT). The effect of solvent in theoretical calculations was included via polarized continuum model (PCM) and the hybrid three-parameter B3LYP density functional in combination with 6-311++G(3df,2pd) basis set enabled calculation of reliable structures of non-ionized (neutral) molecule and its NH and zwitterionic forms in the gas phase, chloroform, DMSO and water. GIAO NMR calculations, using equilibrium and rovibrationally averaged geometry, at B3LYP/6-31G* and B3LYP/aug-cc-pVTZ-J levels of theory provided muscimol nuclear magnetic shieldings. The theoretical proton and carbon chemical shifts were critically compared with experimental NMR spectra measured in DMSO. Our results provide useful information on its structure in solution. We believe that such data could improve the understanding of basic features of muscimol at atomistic level and provide another tool in studies related to GABA analogs.

  20. Cost-effective nanoporous Agar-Agar polymer/Nickel powder composite particle for effective bio-products adsorption by expanded bed chromatography.

    Science.gov (United States)

    Asgari, Setareh; Jahanshahi, Mohsen; Rahimpour, Ahmad

    2014-09-26

    In the present work a novel kind of dense nanoporous composite matrix for expanded bed application has been successfully first prepared with Nickel powder as a densifier and was covered with Agar-Agar layer as a skeleton, through the method of water-in-oil emulsification. Agar-Agar is a porous and inexpensive polymer. In order to fabricate cost-effective adsorbent with favorable qualities Agar-Agar polymer was used. Thereafter, the customized composite particle was modified by pseudo-affinity dye-ligand, Reactive Blue 4 (RB4), aimed at preparing a pseudo-affinity adsorbent (RB4-Agar-Ni) for bioprodut adsorption from aqueous solution. Bovine Serum Albumin (BSA) was selected as a model protein to investigate the adsorption behavior in batchwise and expanded bed chromatography, and the obtained results were evaluated with that of Streamline™ (Amersham-Pharmacia Biotech, Sweden). Spherical appearance and porous structure of composite particles were observed by the optical microscope (OM) and scanning electronic microscope (SEM). The results suggested that the matrices followed the logarithmic normal size distribution with the range of 65-300 μm and average diameter of 126.81-151.47 μm, proper wet density of 1.64-2.78 g/ml, water content of 62.74-34%, porosity of 98-90% and pore size of about 38-130 nm. For better comprehension of the impact of solid phase properties on the performance of the expanded bed, the expansion and hydrodynamic properties of a composite matrix with a series of densities was evaluated and estimated by the retention time distribution method (RTD) in an expanded bed and was compared with that of other matrices. According to obtained results the expansion factors under the same fluid velocity decreased by increasing the matrix density. Moreover, the axial dispersion coefficient (Dax) is the most appropriate parameter for evaluating the stability of expanded bed, on various operating conditions, such as different flow velocity, bed expansion

  1. Long-term biological hydrogen production by agar immobilized Rhodobacter capsulatus in a sequential batch photobioreactor.

    Science.gov (United States)

    Elkahlout, Kamal; Alipour, Siamak; Eroglu, Inci; Gunduz, Ufuk; Yucel, Meral

    2017-04-01

    In this study, agar immobilization technique was employed for biological hydrogen production using Rhodobacter capsulatus DSM 1710 (wild type) and YO3 (hup-mutant) strains in sequential batch process. Different agar and glutamate concentrations were tested with defined nutrient medium. Agar concentration 4% (w/v) and 4 mM glutamate were selected for bacterial immobilization in terms of rate and longevity of hydrogen production. Acetate concentration was increased from 40 to 60-100 and 60 mM gave best results with both bacterial strains immobilized in 4% (w/v) agar. Cell concentration was increased from 2.5 to 5 mg dcw mL -1 agar and it was found that increasing cell concentration of wild-type strain caused decrease in yield and productivity while these parameters improved by increasing cell concentration of mutant strain. Also, the hydrogen production time has extended from 17 days up to 60 days according to the process conditions and parameters. Hydrogen production by immobilized photosynthetic bacteria is a convenient technology for hydrogen production as it enables to produce hydrogen with high organic acid concentrations comparing to suspended cultures. Besides, immobilization increases the stability of the system and allowed sequential batch operation for long-term application.

  2. Stool cultures for Shigella spp: improved specificity by using MacConkey agar with xylose.

    Science.gov (United States)

    Altwegg, M; Buser, J; von Graevenitz, A

    1996-03-01

    A total of 678 stool specimens were cultured on four different agars: on xylose-lysine-desoxycholate agar (XLD), MacConkey agar (Mac), MacConkey agar supplemented with xylose (Mac-X), and Hektoen enteric agar (HE). Isolation rates for shigellae were 77% on HE, 86% on Mac and Mac-X, and 91% on XLD. The specificities of the media were 61% for Mac, 75% for HE, and 78% for XLD and Mac-X. After overnight incubation, Mac-X is much easier to read than XLD, which requires incubation for at least 22 hours. Based on these results and also on the practical aspect that incubation for 22-21 hours does not fit well in our schedule, we now use Mac-X whenever shigellae need to be looked for (i.e. mainly patients with recent travel to tropical countries). As compared to our previous procedure the workload in the laboratory could be reduced by about 20%.

  3. Effects of shape and size of agar gels on heating uniformity during pulsed microwave treatment.

    Science.gov (United States)

    Soto-Reyes, Nohemí; Temis-Pérez, Ana L; López-Malo, Aurelio; Rojas-Laguna, Roberto; Sosa-Morales, María Elena

    2015-05-01

    Model gel systems with different shape (sphere, cylinder, and slab) and size (180 and 290 g) were prepared with agar (5%) and sucrose (5%). Dielectric constant (ε'), loss factor (ε"), thermophysical properties, and temperature distribution of the model system were measured. Each agar model system was immersed and suspended in water, and then, heated in a microwave oven with intermittent heating until the core temperature reached 50 °C. The ε' and ε" of agar gels decreased when frequency increased. The density and thermal conductivity values of the agar gels were 1033 kg/m(3) and 0.55 W/m °C, respectively. The temperature distribution of sphere, cylinder, and slab was different when similar power doses were applied. The slab reached 50 °C in less time (10 min) and showed a more uniform heating than spheres and cylinders in both sizes. Agar model systems of 180 g heated faster than those of 290 g. The coldest point was the center of the model systems in all studied cases. Shape and size are critical food factors that affect the heating uniformity during microwave heating processes. © 2015 Institute of Food Technologists®

  4. Combination of fibrin-agarose hydrogels and adipose-derived mesenchymal stem cells for peripheral nerve regeneration

    Science.gov (United States)

    Carriel, Víctor; Garrido-Gómez, Juan; Hernández-Cortés, Pedro; Garzón, Ingrid; García-García, Salomé; Sáez-Moreno, José Antonio; Sánchez-Quevedo, María del Carmen; Campos, Antonio; Alaminos, Miguel

    2013-04-01

    Objective. The objective was to study the effectiveness of a commercially available collagen conduit filled with fibrin-agarose hydrogels alone or with fibrin-agarose hydrogels containing autologous adipose-derived mesenchymal stem cells (ADMSCs) in a rat sciatic nerve injury model. Approach. A 10 mm gap was created in the sciatic nerve of 48 rats and repaired using saline-filled collagen conduits or collagen conduits filled with fibrin-agarose hydrogels alone (acellular conduits) or with hydrogels containing ADMSCs (ADMSC conduits). Nerve regeneration was assessed in clinical, electrophysiological and histological studies. Main results. Clinical and electrophysiological outcomes were more favorable with ADMSC conduits than with the acellular or saline conduits, evidencing a significant recovery of sensory and motor functions. Histological analysis showed that ADMSC conduits produce more effective nerve regeneration by Schwann cells, with higher remyelination and properly oriented axonal growth that reached the distal areas of the grafted conduits, and with intensely positive expressions of S100, neurofilament and laminin. Extracellular matrix was also more abundant and better organized around regenerated nerve tissues with ADMSC conduits than those with acellular or saline conduits. Significance. Clinical, electrophysiological and histological improvements obtained with tissue-engineered ADMSC conduits may contribute to enhancing axonal regeneration by Schwann cells.

  5. Glass bead cultivation of fungi: combining the best of liquid and agar media.

    Science.gov (United States)

    Droce, Aida; Sørensen, Jens Laurids; Giese, Henriette; Sondergaard, Teis Esben

    2013-09-01

    Production of bioactive compounds and enzymes from filamentous fungi is highly dependent on cultivation conditions. Here we present an easy way to cultivate filamentous fungi on glass beads that allow complete control of nutrient supply. Secondary metabolite production in Fusarium graminearum and Fusarium solani cultivated on agar plates, in shaking liquid culture or on glass beads was compared. Agar plate culture and glass bead cultivation yielded comparable results while liquid culture had lower production of secondary metabolites. RNA extraction from glass beads and liquid cultures was easier than from agar plates and the quality was superior. The system allows simple control of nutrient availability throughout fungal cultivation. This combined with the ease of extraction of nucleic acids and metabolites makes the system highly suitable for the study of gene regulation in response to specific nutrient factors. © 2013.

  6. Effects of disinfection of combined agar/alginate impressions on the dimensional accuracy of stone casts.

    Science.gov (United States)

    Hiraguchi, Hisako; Nakagawa, Hisami; Kaketani, Masahiro; Hirose, Hideharu; Nishiyama, Minoru

    2007-05-01

    This study investigated the effects of disinfection of combined agar/alginate impressions on the dimensional accuracy of resultant stone casts. Impressions of a master cast designed to simulate an abutment tooth were prepared by combining each of two brands of cartridge-form agar impression materials with an alginate impression material. The impressions were immersed in 1% sodium hypochlorite for 10 minutes or 2% glutaraldehyde for 30 minutes. The remaining impressions were sprayed with these two disinfectants and then stored in sealed bags for 10, 30, 60, and 120 minutes. Stone casts obtained from the non-disinfected impressions were also prepared as control. Changes in diameter of the stone casts were then measured. Results indicated that storage for 10 minutes after spraying with 1% sodium hypochlorite was an appropriate disinfection method for combined agar/alginate impressions, as well as immersion in 1% sodium hypochlorite for 10 minutes.

  7. Homogeneous matrix deposition on dried agar for MALDI imaging mass spectrometry of microbial cultures.

    Science.gov (United States)

    Hoffmann, Thomas; Dorrestein, Pieter C

    2015-11-01

    Matrix deposition on agar-based microbial colonies for MALDI imaging mass spectrometry is often complicated by the complex media on which microbes are grown. This Application Note demonstrates how consecutive short spray pulses of a matrix solution can form an evenly closed matrix layer on dried agar. Compared with sieving dry matrix onto wet agar, this method supports analyte cocrystallization, which results in significantly more signals, higher signal-to-noise ratios, and improved ionization efficiency. The even matrix layer improves spot-to-spot precision of measured m/z values when using TOF mass spectrometers. With this technique, we established reproducible imaging mass spectrometry of myxobacterial cultures on nutrient-rich cultivation media, which was not possible with the sieving technique. Graphical Abstract ᅟ.

  8. Digital image quantification of siderophores on agar plates

    Directory of Open Access Journals (Sweden)

    Megan Y. Andrews

    2016-03-01

    Full Text Available This article presents visual image data and detailed methodology for the use of a new method for quantifying the exudation of siderophores during fungal growth. The data include images showing time series for calibration, fungal exudation, and negative controls, as well as replication accuracy information. In addition, we provide detailed protocols for making CAS assay layer plates, the digital analysis protocol for determining area of color change, and discuss growth media that do and do not work with the layer plate method. The results of these data, their interpretation, and further discussion can be found in Andrews et al., 2016 [1].

  9. Influence of agar concentration on in vitro multiplication of Cymbopogon citratus (D. C. Stapf

    Directory of Open Access Journals (Sweden)

    Ricardo J. Licea Moreno

    2001-04-01

    Full Text Available Here are presented the results on in vitro multiplication of lemon grass (Cymbopogon citratus (D. C. Stapf.; it is a very important medicinal plant because its analgesic, antinflamatory and hipotensor properties, among others, useful to elaborate several medicaments with a high popular acceptation. The main aim of this research was to set up the influence of agar concentration in culture medium during in vitro establishment on multiplication of lemon grass. Were used three treatments: (1 liquid medium with filter paper bridges, (2 3 g.l-1 of agar (BIOCEN and (3 6 g.l-1 of agar (BIOCEN. The explants were inoculated on a culture media containing Murashige and Skoog salts (1962, Heinz and Mee vitamins (1969, myoinositol 100 mg.l-1, 6-BAP 0.2 mg.l-1 and sucrose 20 g.l-1. Meristematic tips were inoculated on the treatments described above under sun light conditions, once desinfected. The explants Influence of agar concentration on in vitro multiplication of Cymbopogon citratus (D. C. Stapf. were maintained 21 days in this culture media and later it is were subcultured 5 times each 21 days, on the same multiplication culture media containing Murashige and Skoog salts (1962, tiamine 1 mg.l-1, myoinositol 100 mg.l-1, 6-BAP 0.3 mg.l-1 and sucrose 30 g.l-1. The pH was 5.7 for all culture media. The results showed the relevance of agar concentration during in vitro establishment on multiplication of lemon grass. Differences among treatments until the 2nd subculture was observed. 3.43 new axillary shoots from each explant cultured on a culture media supplemented with 3 g.l-1 of agar was reached. Key words: lemon grass, medicinal plants, micropropagation, tissue culture

  10. Radiation effects on agar, alginates and carrageenan to be used as food additives

    Science.gov (United States)

    Aliste, A. J. A. J.; Vieira, F. F. F. F.; Del Mastro, N. L. N. L.

    2000-03-01

    Agar, alginates and carrageenan are hydrocolloids that induce stabilization of physical properties of the food product during shelf life and prevention of undesirable changes such as moisture migration, gas cell coalescence or textural profile changes. In this work, agar, alginates and carrageenan was irradiated as powder with different doses (0-10 kGy) of Co-60 and the rheological functional performance of water solutions of these irradiated additives was studied. The results are analyzed taking in account the future applications of those additives in irradiated foods.

  11. Glass bead cultivation of fungi - combining the best of liquid and agar media

    DEFF Research Database (Denmark)

    Droce, Aida; Sørensen, Jens Laurids; Giese, Henriette

    2013-01-01

    Production of bioactive compounds and enzymes from filamentous fungi is highly dependent on cultivation conditions. Here we present an easy way to cultivate filamentous fungi on glass beads which allow complete control of nutrient supply. Secondary metabolite production in Fusarium graminearum...... and Fusarium solani cultivated on agar plates, in shaking liquid culture or on glass beads was compared. Agar plate culture and glass bead cultivation yielded comparable results while liquid culture had lower production of secondary metabolites. RNA extraction from glass beads and liquid cultures was easier...

  12. The presence of embedded bacterial pure cultures in agar plates stimulate the culturability of soil bacteria

    DEFF Research Database (Denmark)

    Burmølle, Mette; Johnsen, Kaare; Abu Al-Soud, Waleed Mohamad Abdel F

    2009-01-01

    cultures in between two layers of agar. Plates containing either embedded Pseudomonas putida or Arthrobacter globiformis resulted in higher numbers of CFUs of soil bacteria (21% and 38%, respectively) after 833 h of incubation, compared to plates with no embedded strain. This indicates a stimulatory effect...... homology to known sequenced isolates in GenBank were recovered from plates with embedded strains than from those without, which indicate a higher number of potential novel soil isolates. This approach for cultivation is therefore a feasible alternative or supplement to traditional cultivation on agar...

  13. IPN hydrogel nanocomposites based on agarose and ZnO with antifouling and bactericidal properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jingjing, E-mail: jjwang1@hotmail.com; Hu, Hongkai; Yang, Zhonglin; Wei, Jun; Li, Juan

    2016-04-01

    Nanocomposite hydrogels with interpenetrating polymer network (IPN) structure based on poly(ethylene glycol) methyl ether methacrylate modified ZnO (ZnO-PEGMA) and 4-azidobenzoic agarose (AG-N{sub 3}) were prepared by a one-pot strategy under UV irradiation. The hydrogels exhibited a highly macroporous spongelike structure, and the pore size decreased with the increase of the ZnO-PEGMA content. Due to the entanglement and favorable interactions between the two crosslinked networks, the IPN hydrogels exhibited excellent mechanical strength and light transmittance. The maximum compressive and tensile strengths of the IPN hydrogels reached 24.8 and 1.98 MPa respectively. The transparent IPN hydrogels transmitted more than 85% of visible light at all wavelengths (400–800 nm). The IPN hydrogels exhibited anti-adhesive property towards Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), and the bactericidal activity increased with the ZnO-PEGMA content. The incorporation of ZnO-PEGMA did not reduce the biocompatibility of the IPN hydrogels and all the IPN nanocomposites showed negligible cytotoxicity. The present study not only provided a facile method for preparing hydrogel nanocomposites with IPN structure but also developed a new hydrogel material which might be an excellent candidate for wound dressings. - Highlights: • IPN hydrogel nanocomposites were prepared by a one-pot strategy. • The maximum compressive and tensile strengths reached 24.8 and 1.98 MPa. • IPN hydrogels displayed excellent antibacterial activity and cytocompatibility. • This study provided a facile method for preparing IPN hydrogel nanocomposites.

  14. Mucin Agarose Gel Electrophoresis: Western Blotting for High-molecular-weight Glycoproteins.

    Science.gov (United States)

    Ramsey, Kathryn A; Rushton, Zachary L; Ehre, Camille

    2016-06-14

    Mucins, the heavily-glycosylated proteins lining mucosal surfaces, have evolved as a key component of innate defense by protecting the epithelium against invading pathogens. The main role of these macromolecules is to facilitate particle trapping and clearance while promoting lubrication of the mucosa. During protein synthesis, mucins undergo intense O-glycosylation and multimerization, which dramatically increase the mass and size of these molecules. These post-translational modifications are critical for the viscoelastic properties of mucus. As a result of the complex biochemical and biophysical nature of these molecules, working with mucins provides many challenges that cannot be overcome by conventional protein analysis methods. For instance, their high-molecular-weight prevents electrophoretic migration via regular polyacrylamide gels and their sticky nature causes adhesion to experimental tubing. However, investigating the role of mucins in health (e.g., maintaining mucosal integrity) and disease (e.g., hyperconcentration, mucostasis, cancer) has recently gained interest and mucins are being investigated as a therapeutic target. A better understanding of the production and function of mucin macromolecules may lead to novel pharmaceutical approaches, e.g., inhibitors of mucin granule exocytosis and/or mucolytic agents. Therefore, consistent and reliable protocols to investigate mucin biology are critical for scientific advancement. Here, we describe conventional methods to separate mucin macromolecules by electrophoresis using an agarose gel, transfer protein into nitrocellulose membrane, and detect signal with mucin-specific antibodies as well as infrared fluorescent gel reader. These techniques are widely applicable to determine mucin quantitation, multimerization and to test the effects of pharmacological compounds on mucins.

  15. Is inclusion of Sabouraud dextrose agar essential for the laboratory diagnosis of fungal keratitis?

    Directory of Open Access Journals (Sweden)

    Das Sujata

    2010-01-01

    Full Text Available Purpose: To determine whether the inclusion of Sabouraud dextrose agar (SDA is essential in the diagnosis of fungal keratitis. Materials and Methods: Corneal scrapings of 141 patients with microbial keratitis were smeared and cultured. Sheep blood agar (BA, chocolate agar (CA, SDA, non-nutrient agar (NNA with Escherichia coli overlay, and brain heart infusion broth (BHI were evaluated for time taken for growth and cost. The media were also evaluated experimentally for rate of growth and time taken for identification. Results: Twenty-six of 39 patients positive for fungus in corneal scrapings by microscopy were culture-positive. Fungus grew on BA in 22/39, on CA in 18/39, on SDA in 17/39, on NNA in 17/39, and on BHI in 13/39 cases. Growth on SDA was higher in ulcers with larger infiltrate (6/18 versus 9/13, P = 0.04. Estimated saving with inclusion of only BA/CA was Rs. 600 per patient. Performance of all media was similar in in vitro experiment although the characteristic spores and color were seen earlier on SDA. Conclusion: Fungal keratitis can be reliably confirmed on BA or CA, which support growth of both bacteria and fungus.

  16. Preparation and characterization of bio-nanocomposite films of agar and silver nanoparticles: laser ablation method.

    Science.gov (United States)

    Rhim, Jong-Whan; Wang, Long-Feng; Lee, Yonghoon; Hong, Seok-In

    2014-03-15

    Silver nanoparticles (AgNPs) were prepared by a laser ablation method and composite films with the AgNPs and agar were prepared by solvent casting method. UV-vis absorbance test and transmission electron microscopy (TEM) analysis results revealed that non-agglomerated spherical AgNPs were formed by the laser ablation method. The surface color of the resulting agar/AgNPs films exhibited the characteristic plasmonic effect of the AgNPs with the maximum absorption peaks of 400-407 nm. X-ray diffraction (XRD) test results also exhibited characteristic AgNPs crystals with diffraction peaks observed at 2θ values of 38.39°, 44.49°, and 64.45°, which were corresponding to (111), (200), and (220) crystallographic planes of face-centered cubic (fcc) silver crystals, respectively. Thermogravimetric analysis (TGA) results showed that thermal stability of the agar/AgNPs composite films was increased by the inclusion of metallic silver. Water vapor barrier properties and surface hydrophobicity of the agar/AgNPs films increased slightly with the increase in AgNPs content but they were not statistically significant (p>0.05), while mechanical strength and stiffness of the composite films decreased slightly (pfilms exhibited distinctive antimicrobial activity against both Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli O157:H7) bacterial pathogens. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Investigation of dental alginate and agar impression materials as a brain simulant for ballistic testing.

    Science.gov (United States)

    Falland-Cheung, Lisa; Piccione, Neil; Zhao, Tianqi; Lazarjan, Milad Soltanipour; Hanlin, Suzanne; Jermy, Mark; Waddell, J Neil

    2016-06-01

    Routine forensic research into in vitro skin/skull/brain ballistic blood backspatter behavior has traditionally used gelatin at a 1:10 Water:Powder (W:P) ratio by volume as a brain simulant. A limitation of gelatin is its high elasticity compared to brain tissue. Therefore this study investigated the use of dental alginate and agar impression materials as a brain simulant for ballistic testing. Fresh deer brain, alginate (W:P ratio 91.5:8.5) and agar (W:P ratio 81:19) specimens (n=10) (11×22×33mm) were placed in transparent Perspex boxes of the same internal dimensions prior to shooting with a 0.22inch caliber high velocity air gun. Quantitative analysis to establish kinetic energy loss, vertical displacement elastic behavior and qualitative analysis to establish elasticity behavior was done via high-speed camera footage (SA5, Photron, Japan) using Photron Fastcam Viewer software (Version 3.5.1, Photron, Japan) and visual observation. Damage mechanisms and behavior were qualitatively established by observation of the materials during and after shooting. The qualitative analysis found that of the two simulant materials tested, agar behaved more like brain in terms of damage and showed similar mechanical response to brain during the passage of the projectile, in terms of energy absorption and vertical velocity displacement. In conclusion agar showed a mechanical and subsequent damage response that was similar to brain compared to alginate. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Detection and Enumeration of Leishmania in Sand Flies Using Agar-Based Media

    Science.gov (United States)

    homogenizing sand flies after bloodfeeding on the infected animals and spreading the homogenate over the surface of agar plates. A great variation in...the number of amastigotes ingested by individual sand flies was demonstrated. Not all amastigotes ingested developed anterior stomodeal infections. Keywords: Reprints; Disease vectors.

  19. Mechanical, Thermal and Surface Investigations of Chitosan/Agar/PVA Ternary Blended Films

    Directory of Open Access Journals (Sweden)

    Esam A. El-Hefian

    2011-01-01

    Full Text Available The mechanical and thermal properties of chitosan/agar/poly vinyl alcohol (CS/AG/PVA ternary blended films having various proportions considering chitosan as the main component were investigated. The various variables static water contact angle such as contact angle, drop base area, drop volume and drop height was also studied in correlation with the variation of time. Results obtained from mechanical measurements showed a noticeable increase in the tensile strength (TS coincided with a sharp decrease in elongation percent at break (E% of blended films with increasing agar and PVA contents. The DSC results prevailed the development of an interaction between chitosan individual components: agar and PVA. Moreover, an enhancement of the wettability of the blends was obtained with increasing agar and PVA contents. It was also found that the pure CS film and the blended films with 90/05/05 and 80/10/10 compositions were more affected by time than blended films with other compositions when the contact angle, the drop height and the drop length were studied as a function of time. In addition, when the drop is initially placed on the substrate, the drop area and the drop volume of all films remained almost constant up to a certain time after which they showed a slight difference with the elapse of time.

  20. Medium dependant production of corymbiferone a novel product from Penicillium hordei cultured on plant tissue agar

    DEFF Research Database (Denmark)

    Overy, David Patrick; Zidorn, C.; Petersen, B.O.

    2005-01-01

    Medium dependant production and the structure elucidation of corymbiferone (1) from the fungus Penicillitan hordei grown on oatmeal and macerated tulip, yellow onion and red onion agars are reported. Compound 1 possesses an unusual oxygenated aromatic structure with a lactone bridge preventing fu...

  1. Hyperspectral image reconstruction using RGB color for foodborne pathogen detection on agar plates

    Science.gov (United States)

    Yoon, Seung-Chul; Shin, Tae-Sung; Park, Bosoon; Lawrence, Kurt C.; Heitschmidt, Gerald W.

    2014-03-01

    This paper reports the latest development of a color vision technique for detecting colonies of foodborne pathogens grown on agar plates with a hyperspectral image classification model that was developed using full hyperspectral data. The hyperspectral classification model depended on reflectance spectra measured in the visible and near-infrared spectral range from 400 and 1,000 nm (473 narrow spectral bands). Multivariate regression methods were used to estimate and predict hyperspectral data from RGB color values. The six representative non-O157 Shiga-toxin producing Eschetichia coli (STEC) serogroups (O26, O45, O103, O111, O121, and O145) were grown on Rainbow agar plates. A line-scan pushbroom hyperspectral image sensor was used to scan 36 agar plates grown with pure STEC colonies at each plate. The 36 hyperspectral images of the agar plates were divided in half to create training and test sets. The mean Rsquared value for hyperspectral image estimation was about 0.98 in the spectral range between 400 and 700 nm for linear, quadratic and cubic polynomial regression models and the detection accuracy of the hyperspectral image classification model with the principal component analysis and k-nearest neighbors for the test set was up to 92% (99% with the original hyperspectral images). Thus, the results of the study suggested that color-based detection may be viable as a multispectral imaging solution without much loss of prediction accuracy compared to hyperspectral imaging.

  2. Tapioca-a new and cheaper alternative to agar for direct in vitro ...

    African Journals Online (AJOL)

    Within 11-14% of tapioca, the existence of a favourable osmotic environment and better carbohydrate and/ or ionic supplement to the culture medium than agar is suspected causing improved cell growth and morphogenesis. The result showed the possibility of a successful use of tapioca, a cheaper gelling substance, for in ...

  3. A modified micro chamber agar spot slide culture technique for microscopic examination of filamentous fungi.

    Science.gov (United States)

    Prakash, Peralam Yegneswaran; Bhargava, Kanika

    2016-04-01

    The slide culture technique aids in the study of undisturbed microscopic morphological details of filamentous fungi. The existing methods for setting up of slide culture are quite cumbersome, time-consuming and require elaborate preparation. We describe a modified and easy to perform micro chamber agar spot slide culture technique. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Colwellia agarivorans sp. nov., an agar-digesting marine bacterium isolated from coastal seawater

    Science.gov (United States)

    A novel Gram-stain-negative, facultatively anaerobic, yellowish and agar-digesting marine bacterium, designated strain QM50**T, was isolated from coastal seawater in an aquaculture site near Qingdao, China. Phylogenetic analysis based on 16S rDNA sequences revealed that the novel isolate represented...

  5. Cell cytotoxicity and mycotoxin and secondary metabolite production by common penicillia on cheese agar

    DEFF Research Database (Denmark)

    Gareis, M.; Larsen, Thomas Ostenfeld; Frisvad, Jens Christian

    2002-01-01

    Known or potential new fungal starter culture species such as Penicillium camemberti, P. roqueforti, P. nalgiovense, P. caseifulvum, and P. solitum have been cultivated on a cheese agar medium together with the common cheese contaminants P. commune, P. crustosum, P. discolor, P. atramentosum, and P...

  6. Effects of season on the yield and quality of agar from Gelidium ...

    African Journals Online (AJOL)

    The aim of this work was to study the seasonal variations in the yield and physicochemical properties of agar of Gelidium sesquipedale. The algae were col lected from January 2011 to December 2011, from the coast of Mostaganem, western Algeria. The overall results show that the dry biomass of Gelidium sesquipedale ...

  7. Medium dependant production of corymbiferone a novel product from Penicillium hordei cultured on plant tissue agar

    DEFF Research Database (Denmark)

    Overy, David Patrick; Zidorn, C.; Petersen, B.O.

    2005-01-01

    Medium dependant production and the structure elucidation of corymbiferone (1) from the fungus Penicillitan hordei grown on oatmeal and macerated tulip, yellow onion and red onion agars are reported. Compound 1 possesses an unusual oxygenated aromatic structure with a lactone bridge preventing full...

  8. Colony formation in agar: in vitro assay for haemopoietic stem cells

    NARCIS (Netherlands)

    Dicke, K.A.; Platenburg, M.G.C.; Bekkum, D.W. van

    1971-01-01

    Using a method in which embryo fibroblasts were used as feeder layers, the colony forming capacity in agar of a variety of mouse haemopoietic suspensions was compared with their CFUs content. A striking parallelism between the results of the two assays was found. In addition, under certain

  9. Phenotypic differentiation of species from Aspergillus section Flavi on neutral red desiccated coconut agar

    DEFF Research Database (Denmark)

    Atanda, O. O.; Adetunji, M. C.; Ezekiel, C. N.

    2014-01-01

    In order to facilitate easy and rapid identification of aflatoxin-producing Aspergillus species, the phenotypic traits of Aspergillus section Flavi isolates were examined on neutral red desiccated coconut agar (NRDCA). Phenotype variations in colony morphology and the relationship between colour...

  10. Growth and study of barium oxalate single crystals in agar gel

    Indian Academy of Sciences (India)

    Barium oxalate was grown in agar gel at ambient temperature. The effect of various parameters like gel concentration, gel setting time and concentration of the reactants on the growth of these crystals was studied. Prismatic platy shaped spherulites and dendrites were obtained. The grown crystals were characterized by ...

  11. Distribution assessment comparing continuous and periodic wound instillation in conjunction with negative pressure wound therapy using an agar-based model.

    Science.gov (United States)

    Rycerz, Anthony M; Slack, Paul; McNulty, Amy K

    2013-04-01

    Negative pressure wound therapy (NPWT) is a widely accepted and effective treatment for various wound types, including complex wounds. Negative pressure with instillation was initially used as a gravity-fed system whereby reticulated, open-cell foam in the wound bed was periodically exposed to cycles of soaking with instillation solution followed by NPWT. Recent publications have alluded to positive outcomes with continuous instillation, where fluid is delivered simultaneously with negative pressure. To evaluate the distribution of instillation solutions to wound beds in conjunction with negative pressure, agar-based models were developed and exposed to coloured instillation solutions to identify exposure intensity via agar staining. This model allowed comparison of continuous- versus periodic-instillation therapy with negative pressure. Continuous instillation at a rate of 30 cc/hour with negative pressure showed isolated exposure of instillation fluid to wound beds in agar wound models with and without undermining and tunnelling. In contrast, periodic instillation illustrated uniform exposure of the additive to the entire wound bed including undermined and tunnel areas, with increased staining with each instillation cycle. These findings suggest that periodic instillation facilitates more uniform exposure throughout the wound, including tunnels and undermining, to instillation solutions, thereby providing therapy consistent with the clinician-ordered treatment. © 2012 The Authors. International Wound Journal © 2012 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

  12. Use of Dehydrated Agar to Estimate Microbial Water Quality for Horticulture Irrigation.

    Science.gov (United States)

    Meador, Dustin P; Fisher, Paul R; Guy, Charles L; Harmon, Philip F; Peres, Natalia A; Teplitski, Max

    2016-07-01

    Petrifilms are dehydrated agar culture plates that have been used to quantify colony forming units (CFU) mL of either aerobic bacteria (Petrifilm-AC) or fungus (Petrifilm-YM), depending on substrate composition. Microbes in irrigation systems can indicate biofilm risk and potential clogging of irrigation emitters. The research objective was to compare counts on Petrifilms versus traditional, hydrated-agar plates using samples collected from recirculated irrigation waters and cultures of isolated known species. The estimated count (in CFU mL) from a recirculated irrigation sample after 7 d of incubation on Petrifilm-YM was only 5.5% of the count quantified using sabouraud dextrose agar (SDA) with chloramphenicol after 14 d. In a separate experiment with a known species, Petrifilm-YM did not successfully culture zoospores of . Isolates of viable zoospores were cultured successfully on potato-dextrose agar (PDA), with comparable counts with a vegetable juice medium supplemented with the antibiotics pimaricin, ampicillin, rifamycin, pentochloronitrobenzene and hymexazol (PARP-H). The quantification of pv. Begoniaceae on Petrifilm-AC was not significantly different ( < 0.05) than on PDA, but was lower than on Reasoner and Goldrich agar (R2A) or with a hemocytometer. The current formulation of Petrifilm-YM is unlikely to be a useful monitoring method for plant pathogens in irrigation water because of the inability to successfully culture oomycetes. However, Petrifilm-AC was an effective method to quantify bacteria and can provide an easy-to-use on-farm tool to monitor biofilm risk and microbial density. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  13. Evaluation of MRSA chrome agar for the detection of methicillin resistant staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Durdana Chowdhury

    2013-01-01

    Full Text Available The aim of this study was to evaluate the efficacy of MRSA Chrome agar to detect methicillin resistant Staphylococcus aureus (MRSA and compare it with 1µg oxacillin disc diffusion tests and detection of mecA gene by PCR. A total 116 Staphylococcus aureus (S. aureus, isolated from various clinical samples, were obtained from three tertiary care hospitals of Dhaka city. S. aureus was identified by colony characters, Gram stain and standard biochemical procedures. MRSA was detected by susceptibility to 1µg oxacillin disc, growth of denim blue color colonies of S. aureus on the Brilliance MRSA Chrome agar at 24 and 48 hours of incubation. PCR was performed for amplification of mecA gene as a gold standard method. Out of 116 isolated S. aureus, 33 (28.44% were MRSA by oxacillin disc diffusion test where mecA gene was detected in 28 strains. On MRSA Chrome agar, 29 (25.0% S. aureus produced denim blue colonies at 24 hours, of which 28 isolates possessed mecA gene. At 48 hours incubation, an additional 4 isolates yielded denim blue colonies from which mecA gene could not be identified. All the strains of S. aureus that produced denim blue colonies at 24 and 48 hours were resistant to oxacillin. The sensitivity, specificity and accuracy of oxacillin disc diffusion test were 100%, 94.31% and 95.68% and Chrome agar at 24 hours were 100%, 98.86% and 99.13% respectively. Thus MRSA Chrome agar could be good choice in clinical microbiology laboratory for rapid and accurate identification of MRSA. Ibrahim Med. Coll. J. 2013; 7(1: 1-4

  14. Immobilization of the acylase from Escherichia coli on glyoxyl-agarose gives efficient catalyst for the synthesis of cephalosporins.

    Science.gov (United States)

    Estruch, Ilona; Tagliani, Auro R; Guisán, José Manuel; Fernández-Lafuente, Roberto; Alcántara, Andrés R; Toma, Lucio; Terreni, Marco

    2008-01-01

    The catalytic properties of penicillin G acylase (PGA) from Escherichia coli, when used in kinetically controlled N-acylation (kcNa) of cephalosporanic nuclei, can be strongly influenced by the moiety in 3-position of the cephem structure. In the synthesis of Cefonicid (1c), the adsorption of the cephalosporanic nucleus (7-SACA) in the PGA active site appeared sensitively increased by a positive ionic interaction between an arginine (ArgA145) in the enzyme active site and the sulphonic group of the β-lactam structure. Interestingly, when PGA was immobilized on solid supports, any effect depending on the substrate structure resulted minimized; the catalytic properties of this enzyme were affected with different outcomes depending on the type of matrix and binding chemistry. The PGA immobilized on glyoxyl-agarose (hydrophilic support activated with aldehyde groups) resulted in a good catalyst when used in kinetically controlled N-acylation of different cephalosporanic nuclei. This derivatives allow much better Vs/Vh(1) (defined as the ratio between the rate of synthesis and the rate of hydrolysis of the acylating agent) than the same enzyme immobilized on Eupergit C, an acrylic hydrophobic supports activated with epoxy groups. The synthetic performances of the Eupergit derivative versus different nuclei were always much poorer if compared with glyoxyl-agarose or the soluble protein. The use of PGA immobilized on glyoxyl-agarose allowed the development of efficient processes for the preparation of Cefazolin in high yield and purity. The results obtained in the optimization of this process are presented.

  15. Comparative analysis of thyroid extract gel filtration by dextran gel (Sephadex G-200) and agarose (Sepharose 6-B)

    International Nuclear Information System (INIS)

    Rosenthal, D.; Netto, M.; Silva, M.M. da; Fridman, J.

    1974-01-01

    Separation of thyroglobulin and havier proteins from crude thyroid gland extracts using molecular through agarose gel (Sepharose-6B) is done. In order to compare the separation obtained on Sephadex wiht that on Sepharose, parallel filtrations are run with extratcts from two thyroid adenomas, one 'cold' and one 'hot' nodule, and their normal contralateral tissues. On Sephadex, good separation is ibtained between the heavy proteins and thyroglobulin, separation between thyroglobulin and proteins is better ou Sephacex than on Sepharose althrough, due to the smaller diluition which the lighter fraction suffers on Sephadex, an efficient qualitative analysis is possible [pt

  16. Use of prawn blood agar hemolysis to screen for bacteria pathogenic to cultured tiger prawns Penaeus monodon.

    Science.gov (United States)

    Chang, C I; Liu, W Y; Shyu, C Z

    2000-11-14

    A newly developed prawn blood agar consisting of 1 ml of tiger prawn hemolymph in medium containing 200 ppm Rose Bengal was used to determine the hemolytic activity of 35 isolates of bacteria obtained from cultured tiger prawns Penaeus monodon and their rearing water. For comparison, the hemolytic activity of these isolates was also determined in sheep blood agar. Nine isolates (25.7% of total) showed different hemolytic reactions on prawn blood agar and sheep blood agar. From the 35 isolates, 8 with various hemolytic characteristics were selected and the relationship between the type of hemolytic activity and pathogenicity was determined and compared. Four isolates that showed hemolytic activity in prawn blood agar caused high mortality to cultured tiger prawns. By contrast, a significantly lower mortality rate was observed for tiger prawns injected with 4 isolates that did not exhibit hemolytic activity on prawn blood agar. Results further showed that mortality did not correlate with hemolytic activity determined using sheep blood agar. Prawn blood agar containing P. monodon hemocytes was faster and more accurate for determining prawn hemolytic activity of bacterial isolates.

  17. Differentiating non-0157:H7 STEC serogroups from ground beef plated on agar media by hyperspetral imaging

    Science.gov (United States)

    Introduction: The development of an assay to detect and confirm a positive non-O157:H7 isolate is challenging when mixed morphologically results are obtained from the serogroups growing on Rainbow agar. Rainbow agar is only claimed by the manufacturer to be very specific for E.coli O157:H7 strain...

  18. Agar Sediment Test for Assessing the Suitability of Organic Waste Streams for Recovering Nutrients by the Aquatic Worm Lumbriculus variegatus

    NARCIS (Netherlands)

    Laarhoven, Bob; Elissen, H.J.H.; Temmink, H.; Buisman, C.J.N.

    2016-01-01

    An agar sediment test was developed to evaluate the suitability of organic waste streams from the food industry for recovering nutrients by the aquatic worm Lumbriculus variegatus (Lv). The effects of agar gel, sand, and food quantities in the sediment test on worm growth, reproduction, and water

  19. On the quantitative Amido Black B staining of protein spots in agar gel at low local protein concentrations

    NARCIS (Netherlands)

    Jansen, M.T.

    1962-01-01

    Protein spots in agar gel of identical protein content but different in surface area are found to bind different amounts of dye upon staining with Amido Black B. The lower the protein concentration within the agar gel, the more the Amido Black B content of the spot falls short of the value expected

  20. Agar Sediment Test for Assessing the Suitability of Organic Waste Streams for Recovering Nutrients by the Aquatic Worm Lumbriculus variegatus.

    Directory of Open Access Journals (Sweden)

    Bob Laarhoven

    Full Text Available An agar sediment test was developed to evaluate the suitability of organic waste streams from the food industry for recovering nutrients by the aquatic worm Lumbriculus variegatus (Lv. The effects of agar gel, sand, and food quantities in the sediment test on worm growth, reproduction, and water quality were studied. Agar gel addition ameliorated growth conditions by reducing food hydrolysis and altering sediment structure. Best results for combined reproduction and growth were obtained with 0.6% agar-gel (20 ml, 10 g. fine sand, 40 g. coarse sand, and 105 mg fish food (Tetramin. With agar gel, ingestion and growth is more the result of addition of food in its original quality. Final tests with secondary potato starch sludge and wheat bran demonstrated that this test is appropriate for the comparison of solid feedstuffs and suspended organic waste streams. This test method is expected to be suitable for organic waste studies using other sediment dwelling invertebrates.

  1. The bactericidal effect of carbon nanotube/agar composites irradiated with near-infrared light on Streptococcus mutans

    International Nuclear Information System (INIS)

    Akasaka, Tsukasa; Matsuoka, Makoto; Hashimoto, Takeshi; Abe, Shigeaki; Uo, Motohiro; Watari, Fumio

    2010-01-01

    Dental caries are mainly associated with oral pathogens, and Streptococcus mutans is a primary cariogenic organism. Many methods have been established to eliminate S. mutans from the oral cavity. This study aimed to evaluate the effect of carbon nanotube (CNT)/agar composites irradiated with near-infrared (NIR) light on S. mutans, as a potential photothermal antimicrobial nanotherapy. A colony-forming unit assay clearly showed that CNT/agar composites attain bactericidal activity after NIR light irradiation; this bactericidal activity is higher than that of graphite (GP)/agar and activated carbon (AC)/agar composites. Furthermore, it was observed that longer irradiation times immobilized S. mutans in the CNT/agar composite.

  2. The bactericidal effect of carbon nanotube/agar composites irradiated with near-infrared light on Streptococcus mutans

    Energy Technology Data Exchange (ETDEWEB)

    Akasaka, Tsukasa, E-mail: akasaka@den.hokudai.ac.jp [Graduate School of Dental Medicine, Hokkaido University, Kita13 Nishi7, Kita-ku, Sapporo 060-8586 (Japan); Matsuoka, Makoto [Graduate School of Dental Medicine, Hokkaido University, Kita13 Nishi7, Kita-ku, Sapporo 060-8586 (Japan); Hashimoto, Takeshi [Meijo Nano Carbon Co. Ltd., Otsubashi bldg. 4F, 3-4-10 Marunouchi, Naka-ku, Nagoya 460-0002 (Japan); Abe, Shigeaki; Uo, Motohiro; Watari, Fumio [Graduate School of Dental Medicine, Hokkaido University, Kita13 Nishi7, Kita-ku, Sapporo 060-8586 (Japan)

    2010-10-15

    Dental caries are mainly associated with oral pathogens, and Streptococcus mutans is a primary cariogenic organism. Many methods have been established to eliminate S. mutans from the oral cavity. This study aimed to evaluate the effect of carbon nanotube (CNT)/agar composites irradiated with near-infrared (NIR) light on S. mutans, as a potential photothermal antimicrobial nanotherapy. A colony-forming unit assay clearly showed that CNT/agar composites attain bactericidal activity after NIR light irradiation; this bactericidal activity is higher than that of graphite (GP)/agar and activated carbon (AC)/agar composites. Furthermore, it was observed that longer irradiation times immobilized S. mutans in the CNT/agar composite.

  3. Effect of natural and semisynthetic pseudoguianolides on the stability of NF-κB:DNA complex studied by agarose gel electrophoresis.

    Science.gov (United States)

    Villagomez, Rodrigo; Hatti-Kaul, Rajni; Sterner, Olov; Almanza, Giovanna; Linares-Pastén, Javier A

    2015-01-01

    The nuclear factor κB (NF-κB) is a promising target for drug discovery. NF-κB is a heterodimeric complex of RelA and p50 subunits that interact with the DNA, regulating the expression of several genes; its dysregulation can trigger diverse diseases including inflammation, immunodeficiency, and cancer. There is some experimental evidence, based on whole cells studies, that natural sesquiterpene lactones (Sls) can inhibit the interaction of NF-κB with DNA, by alkylating the RelA subunit via a Michael addition. In the present work, 28 natural and semisynthetic pseudoguianolides were screened as potential inhibitors of NF-κB in a biochemical assay that was designed using pure NF-κB heterodimer, pseudoguianolides and a ~1000 bp palindromic DNA fragment harboring two NF-κB recognition sequences. By comparing the relative amount of free DNA fragment to the NF-κB - DNA complex, in a routine agarose gel electrophoresis, the destabilizing effect of a compound on the complex is estimated. The results of the assay and the following structure-activity relationship study, allowed the identification of several relevant structural features in the pseudoguaianolide skeleton, which are necessary to enhance the dissociating capacity of NF-κB-DNA complex. The most active compounds are substituted at C-3 (α-carbonyl), in addition to having the α-methylene-γ-lactone moiety which is essential for the alkylation of RelA.

  4. Effect of natural and semisynthetic pseudoguianolides on the stability of NF-κB:DNA complex studied by agarose gel electrophoresis.

    Directory of Open Access Journals (Sweden)

    Rodrigo Villagomez

    Full Text Available The nuclear factor κB (NF-κB is a promising target for drug discovery. NF-κB is a heterodimeric complex of RelA and p50 subunits that interact with the DNA, regulating the expression of several genes; its dysregulation can trigger diverse diseases including inflammation, immunodeficiency, and cancer. There is some experimental evidence, based on whole cells studies, that natural sesquiterpene lactones (Sls can inhibit the interaction of NF-κB with DNA, by alkylating the RelA subunit via a Michael addition. In the present work, 28 natural and semisynthetic pseudoguianolides were screened as potential inhibitors of NF-κB in a biochemical assay that was designed using pure NF-κB heterodimer, pseudoguianolides and a ~1000 bp palindromic DNA fragment harboring two NF-κB recognition sequences. By comparing the relative amount of free DNA fragment to the NF-κB - DNA complex, in a routine agarose gel electrophoresis, the destabilizing effect of a compound on the complex is estimated. The results of the assay and the following structure-activity relationship study, allowed the identification of several relevant structural features in the pseudoguaianolide skeleton, which are necessary to enhance the dissociating capacity of NF-κB-DNA complex. The most active compounds are substituted at C-3 (α-carbonyl, in addition to having the α-methylene-γ-lactone moiety which is essential for the alkylation of RelA.

  5. Root architecture and morphometric analysis of Arabidopsis thaliana grown in Cd/Cu/Zn-gradient agar dishes: A new screening technique for studying plant response to metals.

    Science.gov (United States)

    Bochicchio, Rocco; Sofo, Adriano; Terzano, Roberto; Gattullo, Concetta Eliana; Amato, Mariana; Scopa, Antonio

    2015-06-01

    A new screening strategy using Petri dishes with a gradient of distances between germinating seeds and a metal-contaminated medium was used for studying alterations in root architecture and morphology of Arabidopsis thaliana treated with cadmium, copper and zinc at sub-toxic concentrations. Metal concentrations in the dishes were determined by anodic stripping voltammetry on digested agar samples collected along the gradient, and kriging statistical interpolation method was performed. After two weeks, all agar dishes were scanned at high resolution and the root systems analyzed. In the presence of all the three metals, primary root length did not significantly change compared to controls, excepting for zinc applied alone (+45% of controls). In metal-treated seedlings, root system total length increased due to the higher number of lateral roots. The seedlings closer to the agar sectors including metals showed a marked curvature and a higher root branching in comparison to those further away from the metals. This behavior, together with an observed increase in root diameter in metal-treated seedlings could be interpreted as compensatory growth, and a thicker roots could act as a barrier to protect root from the metals. We therefore propose that the remodeling of the root architecture in response to metals could be a pollution 'escaping strategy' aimed at seeking metal-free patches. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  6. Supplementation of exogenous adenosine 5'-triphosphate enhances mechanical properties of 3D cell-agarose constructs for cartilage tissue engineering.

    Science.gov (United States)

    Gadjanski, Ivana; Yodmuang, Supansa; Spiller, Kara; Bhumiratana, Sarindr; Vunjak-Novakovic, Gordana

    2013-10-01

    Formation of tissue-engineered cartilage is greatly enhanced by mechanical stimulation. However, direct mechanical stimulation is not always a suitable method, and the utilization of mechanisms underlying mechanotransduction might allow for a highly effective and less aggressive alternate means of stimulation. In particular, the purinergic, adenosine 5'-triphosphate (ATP)-mediated signaling pathway is strongly implicated in mechanotransduction within the articular cartilage. We investigated the effects of transient and continuous exogenous ATP supplementation on mechanical properties of cartilaginous constructs engineered using bovine chondrocytes and human mesenchymal stem cells (hMSCs) encapsulated in an agarose hydrogel. For both cell types, we have observed significant increases in equilibrium and dynamic compressive moduli after transient ATP treatment applied in the fourth week of cultivation. Continuous ATP treatment over 4 weeks of culture only slightly improved the mechanical properties of the constructs, without major changes in the total glycosaminoglycan (GAG) and collagen content. Structure-function analyses showed that transiently ATP-treated constructs, and in particular those based on hMSCs, had the highest level of correlation between compositional and mechanical properties. Transiently treated groups showed intense staining of the territorial matrix for GAGs and collagen type II. These results indicate that transient ATP treatment can improve functional mechanical properties of cartilaginous constructs based on chondrogenic cells and agarose hydrogels, possibly by improving the structural organization of the bulk phase and territorial extracellular matrix (ECM), that is, by increasing correlation slopes between the content of the ECM components (GAG, collagen) and mechanical properties of the construct.

  7. Modification of gel architecture and TBE/TAE buffer composition to minimize heating during agarose gel electrophoresis.

    Science.gov (United States)

    Sanderson, Brian A; Araki, Naoko; Lilley, Jennifer L; Guerrero, Gilberto; Lewis, L Kevin

    2014-06-01

    Agarose gel electrophoresis of DNA and RNA is routinely performed using buffers containing either Tris, acetate, and EDTA (TAE) or Tris, borate, and EDTA (TBE). Gels are run at a low, constant voltage (∼10 V/cm) to minimize current and asymmetric heating effects, which can induce band artifacts and poor resolution. In this study, alterations of gel structure and conductive media composition were analyzed to identify factors causing higher electrical currents during horizontal slab gel electrophoresis. Current was reduced when thinner gels and smaller chamber buffer volumes were used, but was not influenced by agarose concentration or the presence of ethidium bromide. Current was strongly dependent on the amount and type of EDTA used and on the concentrations of the major acid-base components of each buffer. Interestingly, resolution and the mobilities of circular versus linear plasmid DNAs were also affected by the chemical form and amount of EDTA. With appropriate modifications to gel structure and buffer constituents, electrophoresis could be performed at high voltages (20-25 V/cm), reducing run times by up to 3-fold. The most striking improvements were observed with small DNAs and RNAs (10-100 bp): high voltages and short run times produced sharper bands and higher resolution. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Separation of galactose, 5-hydroxymethylfurfural and levulinic acid in acid hydrolysate of agarose by nanofiltration and electrodialysis.

    Science.gov (United States)

    Kim, Jae Hyung; Na, Jeong-Geol; Yang, Ji-Won; Chang, Yong Keun

    2013-07-01

    A two-stage membrane process for the separation of galactose, 5-hydroxymethylfurfural (5-HMF) and levulinic acid (LA) has been proposed. The first step of nanofiltration (NF) is to remove 5-HMF and LA from galactose solution obtained by the hydrolysis of agarose, the main component of red algal galactan for the reduction of its microbial toxicity. 5-HMF and LA are inhibitory to fermentation but at the same time useful compounds themselves with many applications. The second step of electrodialysis (ED) is to separate 5-HMF and LA in the permeate from NF. More than 91% of 5-HMF and up to 62% of LA could be removed from agarose hydrolysate, while galactose was almost completely retained by NF. Further removal of LA was expected to be possible with no loss of galactose by operating the NF process in a diafiltration mode. 5-HMF and LA could be effectively separated from each other by ED. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Candida dubliniensis and Candida albicans differentiation by colony morphotype in Sabouraud-triphenyltetrazolium agar.

    Science.gov (United States)

    Gamarra, Soledad; Mancilla, Estefanía; Dudiuk, Catiana; Garcia-Effron, Guillermo

    2015-01-01

    Candida dubliniensis is a germ tube and chlamydoconidia producing Candida species that may be misidentified as Candida albicans. Molecular-based methods are the most reliable techniques for C. albicans and C. dubliniensis differentiation. However, accurate, quick and inexpensive phenotypic tests are needed to be used in low-complexity mycology laboratories. To evaluate colony morphotypes on Sabouraud-triphenyltetrazolium agar as a tool for C. dubliniensis and C. albicans differentiation. The morphology of 126 C. albicans and C. dubliniensis strains was evaluated and compared with their identification by molecular methods. The method showed 100% sensitivity and specificity when color and the presence or absence of large white mycelial halo was evaluated. Colony morphotype on Sabouraud-triphenyltetrazolium agar should be considered as a new tool to differentiate C. dubliniensis and C. albicans. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  10. Sterilization of MacConkey agar and CLED medium by gamma-radiation.

    Science.gov (United States)

    Bogokowsky, B; Eisenberg, E; Altmann, G

    1983-10-01

    MacConkey agar and Cystine-Lactose-Electrolyte-Deficient (CLED) agar, media widely used in the bacteriological laboratory and recommended for the detection of urinary tract infections, were sterilized by gamma-radiation at a dose of 1.5 Mrad. Both were modified and adapted to radiation sterilization by adding sodium thioglycollate as a radioprotectant, and by increasing their indicator content. The media performed well when tested with different Enterobacteria and other micro-organisms. Growth and change of indicator reaction were equal in irradiated and autoclaved culture media. Culture media were also evaluated after storage for one month at room temperature and at 4 degrees C and compared well with freshly autoclaved media.

  11. Sterilization of MacConkey agar and CLED medium by. gamma. -radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bogokowsky, B.; Altmann, G. (Sheba Medical Center, Tel Hashomer (Israel); Tel Aviv Univ. (Israel). Medical School); Eisenberg, E. (Israel Atomic Energy Commission, Yavne. Soreq Nuclear Research Center)

    1983-10-01

    MacConkey agar and Cystine-Lactose-Electrolyte-Deficient (CLED) agar, media widely used in the bacteriological laboratory and recommended for the detection of urinary tract infections, were sterilized by ..gamma..-radiation at a dose of 1.5 Mrad. Both were modified and adapted to radiation sterilization by adding sodium thioglycollate as a radioprotectant, and by increasing their indicator content. The media performed well when tested with different Enterobacteria and other micro-organisms. Growth and change of indicator reaction were equal in irradiated and autoclaved culture media. Culture media were also evaluated after storage for one month at room temperature and at 4/sup 0/C and compared well with freshly autoclaved media.

  12. Sterilization of MacConkey agar and CLED medium by gamma-radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bogokowsky, B.; Eisenberg, E.; Altmann, G.

    1983-10-01

    MacConkey agar and Cystine-Lactose-Electrolyte-Deficient (CLED) agar, media widely used in the bacteriological laboratory and recommended for the detection of urinary tract infections, were sterilized by gamma-radiation at a dose of 1.5 Mrad. Both were modified and adapted to radiation sterilization by adding sodium thioglycollate as a radioprotectant, and by increasing their indicator content. The media performed well when tested with different Enterobacteria and other micro-organisms. Growth and change of indicator reaction were equal in irradiated and autoclaved culture media. Culture media were also evaluated after storage for one month at room temperature and at 4 degrees C and compared well with freshly autoclaved media.

  13. [Physical properties of the agar of Gracilariopsis tenuifrons (Gracilariacea) from Sucre, Venezuela].

    Science.gov (United States)

    Zecchinel, E; Brito, L; Lárez, G

    2000-12-01

    The yield, gel strength, gelling and melting temperatures of Gracilariopsis tenuifrons agar from Guayacán, Araya Peninsula, Sucre State, Venezuela were determined. Yield values with and without alkali treatment ranged from 23.22 to 39.57% and from 16.29 to 22.42% respectively, while gel strength with alkali treatment fluctuated betwen 699.31 and 1231.69 g/cm2 and without treatment varied from 278.0 to 691.06 g/cm2. Gelling and melting temperatures were in the range reported for other agarophytes. Considering gel strength, the agar quality of G. tenuifrons was higher than in other species and its exploitation in economically feasible.

  14. Ground red hot pepper agar in the isolation and presumptive identification of Cryptococcus neoformans.

    Science.gov (United States)

    Stepanović, S; Vuković, D; Radonjić, I; Dimitrijević, V; Svabić-Vlahović, M

    2002-11-01

    The study compared ground red hot pepper agar (GRHP) and Guizotia abyssinica creatinine agar (GACA), a medium routinely used for isolation of Cryptococcus neoformans. In order to confirm the capacity of GRHP to support the Cr. neoformans growth and pigment production, 15 strains were inoculated onto GRHP and GACA. No significant differences in the growth and pigmentation of the tested strains on the two media were noted. As heavily contaminated specimens, 50 samples of pigeon droppings were examined by plating on GRHP and GACA, which resulted in the isolation of 14 and nine Cr. neoformans strains, respectively. The results indicate that GRHP, as a result of its superior selectivity and significant reduction of contaminant growth, provides better conditions than GACA for isolation and presumptive identification of Cr. neoformans from heavily contaminated specimens.

  15. Scintigraphic evidence of the retarded insulin liberation from agar embeddings in suppositories

    International Nuclear Information System (INIS)

    Losse, G.; Mueller, F.; Fischer, S.

    1989-01-01

    It is reported on the retardation and protective effect of insulin-agar-embeddings in triglyceride suppositories by in vitro and in vivo tests on rabbits. The discovered effects were visually followed by gamma scanning of adequate rectally applied 131 I-insulin specimens in the rectum and thyroid gland and, in relation with the glucose lowering course, the liberation, distribution and biovailability of the immobilized hormone was illustrated. (author)

  16. Comparison of the Etest and the routine multi-disc agar diffusion ...

    African Journals Online (AJOL)

    Results: On the Etest strips, Staph aureus was 83.5% sensitive to ciprofloxacin, 52.6% to gentamicin, 48.5% to ampicillin and 8.2% to chloramphenicol while on the multi-disc agar diffusion plates 80.4% of Staph aureus were sensitive to ciprofloxacin, 49.5% to gentamicin, 39.2% to ampicillin and 12.4% to chloramphenicol.

  17. Rapid method for detection of Pseudomonas aeruginosa on MacConkey agar under ultraviolet light.

    Science.gov (United States)

    Brodsky, M H; Nixon, M C

    1973-08-01

    A simple screening technique for the detection of Pseudomonas aeruginosa colonies by their fluorescence on MacConkey agar under ultraviolet light is proposed. From 306 nonlactose fermenting cultures screened under the ultraviolet light, 108 fluorescent isolates were obtained. These were screened biochemically, with 103 (94.8%) being verified as P. aeruginosa. From the 198 nonfluorescing cultures, only one suspected P. aeruginosa was isolated.

  18. Growth of non-Campylobacter, oxidase-positive bacteria on selective Campylobacter agar.

    OpenAIRE

    Moskowitz, L B; Chester, B

    1982-01-01

    A total of 67 oxidase-positive, gram-negative bacteria were tested for growth on selective Campylobacter agar (Blaser formulation, BBL Microbiology Systems, Cockeysville, Md.) at 42 degrees C under microaerophilic conditions. Although the growth of most of these bacteria was prevented, all strains of Achromobacter xylosoxidans, Pseudomonas aeruginosa, Pseudomonas putrefaciens, Pseudomonas alcaligenes, and Pseudomonas pseudoalcaligenes grew as well as Campylobacter fetus subsp. jejuni.

  19. Cytotoxicity of ferrite particles by MTT and agar diffusion methods for hyperthermic application

    International Nuclear Information System (INIS)

    Kim, Dong-Hyun; Lee, Se-Ho; Kim, Kyoung-Nam; Kim, Kwang-Mahn; Shim, In-Bo; Lee, Yong-Keun

    2005-01-01

    We investigated the cytotoxicity of the prepared various ferrites (Fe-, Li-, Ni/Zn/Cu-, Ba-, Sr-, Co-, Co/Ni-ferrites) using MTT assay as well as agar diffusion method. Their cytotoxicity was compared with that of alginate-encapsulated ferrites. In the MTT assay, Fe 3 O 4 and SrFe 12 O 19 ferrite showed the highest cell viability of 90%. Alginate-encapsulated Ba-ferrite was ranked mildly cytotoxic, whereas their ferrite particles were ranked cytotoxic

  20. Comparing the disk-diffusion and agar dilution tests for Neisseria gonorrhoeae antimicrobial susceptibility testing

    Directory of Open Access Journals (Sweden)

    Hsi Liu

    2016-11-01

    Full Text Available Abstract Background We assessed the validity of testing for antimicrobial susceptibility of clinical and mutant Neisseria gonorrhoeae (GC isolates by disk diffusion in comparison to agar dilution, and Etest® (bioMerieux, France, respectively, for three third generation extended spectrum cephalosporins (ESC: ceftriaxone (CRO, cefixime (CFX, and cefpodoxime (CPD. Methods One hundred and five clinical isolates and ten laboratory-mutants were tested following Clinical Laboratory Standard Institute (CLSI and manufacturer’s standards for each of the three methods. The measured diameters by the disk diffusion method were tested for correlation with the MIC values by agar dilution. In addition, comparisons with the Etest® were made. Categorical results for concordance, based on standard CLSI cutoffs, between the disk diffusion and the other two methods, respectively, were tested using the Chi-square statistics. Reproducibility was tested for CFX across a 6-month interval by repeated disk tests. Results Across all 115 specimens, the disk diffusion tests produced good categorical agreements, exhibiting concordance of 93.1%, 92.1%, and 90.4% with agar dilution and 93.0%, 92.1%, and 90.4% with Etest®, for CRO, CFX, and CPD, respectively. Pearson correlations between disk-diffusion diameters and agar dilution MIC’s were -0.59, -0.67, and -0.81 for CRO, CFX, and CPD, respectively. The correlations between disk diffusion and Etest® were -0.58, -0.73, and -0.49. Pearson correlation between the CFX disk readings over a 6-month interval was 91%. Conclusions Disk diffusion tests remain to be a useful, reliable and fast screening method for qualitative antimicrobial susceptibility testing for ceftriaxone, cefixime, and cefpodoxime.

  1. Differentiation between Candida albicans and Candida dubliniensis using hypertonic Sabouraud broth and tobacco agar

    Directory of Open Access Journals (Sweden)

    Fabíola Silveira-Gomes

    2011-08-01

    Full Text Available INTRODUCTION: Opportunistic fungal infections in immunocompromised hosts are caused by Candida species, and the majority of such infections are due to Candida albicans. However, the emerging pathogen Candida dubliniensis demonstrates several phenotypic characteristics in common with C. albicans, such as production of germ tubes and chlamydospores, calling attention to the development of stable resistance to fluconazole in vitro. The aim of this study was to evaluate the performance of biochemistry identification in the differentiating between C. albicans and C. dubliniensis, by phenotyping of yeast identified as C. albicans. METHODS: Seventy-nine isolates identified as C. albicans by the API system ID 32C were grown on Sabouraud dextrose agar at 30°C for 24-48h and then inoculated on hypertonic Sabouraud broth and tobacco agar. RESULTS: Our results showed that 17 (21.5% isolates were growth-inhibited on hypertonic Sabouraud broth, a phenotypic trait inconsistent with C. albicans in this medium. However, the results observed on tobacco agar showed that only 9 (11.4% of the growth-inhibited isolates produced characteristic colonies of C. dubliniensis (rough colonies, yellowish-brown with abundant fragments of hyphae and chlamydospores. CONCLUSIONS: The results suggest that this method is a simple tool for screening C. albicans and non-albicans yeast and for verification of automated identification.

  2. Assessment of agar gel loaded with micro-emulsion for the cleaning of porous surfaces

    Directory of Open Access Journals (Sweden)

    Florence Gorel

    2010-11-01

    Full Text Available Le système composé d’un gel d’agar-agar et d’une microémulsion présente plusieurs qualités pour extraire des matériaux hydrophobes de couches poreuses. Les propriétés rhéologiques de ce système sont adaptées à un usage en restauration et sont stables pendant plusieurs jours. Les gels permettent la solubilisation du matériau à l’aide de faible quantité de solvant, l’empêchent de créer des auréoles, permettent le contrôle de l’évaporation des solvants et ne laissent pas de résidus de gel dans les pores.Agar gel loaded with micro-emulsion could be used to extract lipophilic materials from porous surfaces. The physical properties of the gels are good enough for a conservation work. They allow the micro-emulsion to flow on the porous surface and to wet it but maintain the micro-emulsion in its structure and prevent the formation of rings. The evaporation of the solvents is slowed down and the gels can be used during a long period.

  3. Preparation of bioactive neoagaroligosaccharides through hydrolysis of Gracilaria lemaneiformis agar: A comparative study.

    Science.gov (United States)

    Xu, Xin-Qi; Su, Bing-Mei; Xie, Jin-Sheng; Li, Ren-Kuan; Yang, Jie; Lin, Juan; Ye, Xiu-Yun

    2018-02-01

    Hydrolysis of Gracilaria lemaneiformis agar by β-agarase was compared with HCl hydrolysis. The results showed that optimum catalysis conditions for the β-agarase were pH 7.0 at 45°C. Mass spectroscopy, thin-layer chromatography and GPC results showed that the polymerization degrees of the hydrolysis products by the β-agarase were mainly four, six and eight (more specific than the hydrolysate by HCl). The enzymatic degradation products of agar were distinctly different from those of HCl hydrolysis in the ratios among galactose and 3,6-anhydro-galactose and sulfate group contents. The NMR spectrometry proved that the products of β-agarase were neoagaroligosaccharides, which was not found in the agarolytic products by HCl. The neoagarotetraose inhibited tyrosinase activity competitively with the K I value of 16.0mg/ml. Hydroxyl radical-scavenging ability of neoagaroligosaccharides was much greater than that of agar HCl hydrolysate. This work suggests that neoagaroligosaccharide products produced by our β-agarase could be more effective in function than products from acid hydrolysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Differentiation between Candida albicans and Candida dubliniensis using hypertonic Sabouraud broth and tobacco agar.

    Science.gov (United States)

    Silveira-Gomes, Fabíola; Sarmento, Dayse Nogueira; Espírito-Santo, Elaine Patrícia Tavares do; Souza, Nádia de Oliveira; Pinto, Thifany Mendes; Marques-da-Silva, Silvia Helena

    2011-01-01

    Opportunistic fungal infections in immunocompromised hosts are caused by Candida species, and the majority of such infections are due to Candida albicans. However, the emerging pathogen Candida dubliniensis demonstrates several phenotypic characteristics in common with C. albicans, such as production of germ tubes and chlamydospores, calling attention to the development of stable resistance to fluconazole in vitro. The aim of this study was to evaluate the performance of biochemistry identification in the differentiating between C. albicans and C. dubliniensis, by phenotyping of yeast identified as C. albicans. Seventy-nine isolates identified as C. albicans by the API system ID 32C were grown on Sabouraud dextrose agar at 30°C for 24-48h and then inoculated on hypertonic Sabouraud broth and tobacco agar. Our results showed that 17 (21.5%) isolates were growth-inhibited on hypertonic Sabouraud broth, a phenotypic trait inconsistent with C. albicans in this medium. However, the results observed on tobacco agar showed that only 9 (11.4%) of the growth-inhibited isolates produced characteristic colonies of C. dubliniensis (rough colonies, yellowish-brown with abundant fragments of hyphae and chlamydospores). The results suggest that this method is a simple tool for screening C. albicans and non-albicans yeast and for verification of automated identification.

  5. An agar diffusion study comparing the antimicrobial activity of Nanoseal with some other endodontic sealers.

    Science.gov (United States)

    Aal-Saraj, Ali Burak; Ariffin, Zaihan; Masudi, Sam'an Malik

    2012-08-01

    The aim of this study was to evaluate the antimicrobial activity of a new experimental nano-hydroxyapatite epoxy resin-based sealer (Nanoseal) with several other commercially available sealers; AH26, Tubliseal, Sealapex and Roekoseal against Enterococcus faecalis, Pseudomonas aeruginosa, Streptococcus mutans, Streptococcus sobrinus and Escherichia coli for up to 7 days. Agar diffusion was used in this study. Fifty Muller-Hinton agar plates were prepared and divided into five experimental groups (n = 10), for each micro-organism. Another 10 agar plates were used as positive and negative controls. Endodontic sealers were tested against each micro-organism. Inhibition zones produced were recorded. The results of this study showed that all test materials exhibited inhibition zones towards the tested micro-organisms for 7 days except for Roekoseal, which showed no inhibition zones. Nanoseal and AH26 exhibited similar zones of inhibition. Significant difference was found between Nanoseal and the other tested sealers (P < 0.001). © 2010 The Authors. Australian Endodontic Journal © 2010 Australian Society of Endodontology.

  6. Ground red hot pepper agar in the isolation of yeasts of Candida spp.

    Science.gov (United States)

    Stepanović, S; Djukić, S; Vuković, D; Mitrović, S; Babić, D

    1998-11-01

    The purpose of this study was to investigate and determine the value of a novel, simple and inexpensive selective medium for isolation of yeasts of Candida spp. - ground red hot pepper agar (GRHP). The study compared GRHP and Sabouraud dextrose agar (SDA), an insufficiently selective medium routinely used for primary isolation of yeasts. The comparison was based on qualitative and quantitative characterisation of growth of 25 bacterial strains, measurement of growth of 22 yeast strains and testing on clinical specimens. Qualitative tests on bacteria showed either significantly less growth on GRHP than on SDA, or no growth on GRHP. Quantitative tests confirmed these results; the number of colonies of all tested bacterial species and strains on GRHP was significantly lower than on SDA. With regard to the isolation of Candida spp., GRHP had the same properties as SDA. Statistical analysis showed no significant differences in the growth of Candida spp. and strains on the two media. All these results were confirmed by tests on clinical material. The results clearly show that GRHP agar is an economical medium for the isolation of yeasts of Candida spp., with excellent selectivity.

  7. Application of solid-phase extraction to agar-supported fermentation.

    Science.gov (United States)

    Le Goff, Géraldine; Adelin, Emilie; Cortial, Sylvie; Servy, Claudine; Ouazzani, Jamal

    2013-09-01

    Agar-supported fermentation (Ag-SF), a variant of solid-state fermentation, has recently been improved by the development of a dedicated 2 m(2) scale pilot facility, Platotex. We investigated the application of solid-phase extraction (SPE) to Ag-SF in order to increase yields and minimize the contamination of the extracts with agar constituents. The selection of the appropriate resin was conducted on liquid-state fermentation and Diaion HP-20 exhibited the highest recovery yield and selectivity for the metabolites of the model fungal strains Phomopsis sp. and Fusarium sp. SPE applied to Ag-SF resulted in a particular compartmentalization of the culture. The mycelium that requires oxygen to grow migrates to the top layer and formed a thick biofilm. The resin beads intercalate between the agar surface and the mycelium layer, and trap directly the compounds secreted by the mycelium through a "solid-solid extraction" (SSE) process. The resin/mycelium layer is easily recovered by scraping the surface and the target metabolites extracted by methanol. Ag-SF associated to SSE represents an ideal compromise for the production of bioactive secondary metabolites with limited economic and environmental impact.

  8. Modification of Karmali agar by supplementation with potassium clavulanate for the isolation of Campylobacter from chicken carcass rinses.

    Science.gov (United States)

    Chon, Jung-Whan; Kim, Hong-Seok; Kim, Dong-Hyeon; Kim, Hyunsook; Choi, In-Soo; Oh, Deog-Hwan; Seo, Kun-Ho

    2014-07-01

    The detection ability and selectivity of Karmali agar was improved by supplementation of an extended-spectrum β-lactamase inhibitor, potassium clavulanate. The optimum concentration of potassium clavulanate (0.5 μg/ml) in Karmali agar was determined by inoculation of 50 Campylobacter and 30 extended-spectrum β-lactamase-producing E. coli strains onto normal and modified Karmali agar containing various concentrations of the agent. Eighty retail carcasses were rinsed with 400 ml of buffered peptone water. The rinse samples were enriched in 2 × blood-free Bolton enrichment broth at 42°C for 48 h and then were streaked onto normal and modified Karmali agar containing 0.5 μg/ml potassium clavulanate. The suspicious colonies were subcultured on Columbia blood agar and confirmed by colony PCR. In chicken carcass samples, the modified Karmali agar showed a significantly greater isolation rate than normal Karmali agar (42.5 versus 21.3%; P Campylobacter colonies.

  9. Evaluation of modified dichloran 18% glycerol (DG18) agar for enumerating fungi in wheat flour: a collaborative study.

    Science.gov (United States)

    Beuchat, L R; Hwang, C A

    1996-04-01

    Dichloran 18% glycerol agar base supplemented with 100 micrograms of chloramphenicol ml-1 (DG18 agar) was compared to DG18 agar supplemented with 100 micrograms of Triton X-301 ml-1 (DG18T) and DG18 agar supplemented with 1 microgram of iprodione [3-(3,5-dichlorophenyl)-N-(1-methyl-ethyl)-2,4-dioxo-1-imidazolidine- carboxamide] ml-1 (DG18I agar) for enumeration of fungi in ten brands of wheat flour. As the flours contained low fungal populations, all were inoculated with two to four strains of xerophilic fungi (Aspergillus candidus, A. penicillioides, Eurotium amstelodami, E. intermedium, E. repens, E. rubrum, E. tonophilum, E. umbrosum and Wallemia sebi), after which counts ranged from 3.87 to 6.37 log10 CFU g-1. Significantly higher populations (p sebi grew well on all three media. DG18T agar was judged to be superior to DG18 and DG18I agars for enumerating fungi in wheat flours.

  10. Hydrolysis activities of the particle of agarose-Ce4+ complex for compounds containing phosphodiester or peptide bonds

    Science.gov (United States)

    Yu, Lina; Wang, Dongfeng; Su, Lin; Luo, Yi; Sun, Liping; Xue, Changhu

    2005-07-01

    Hydrolysis activities of PACC (particle of agarose-Ce4+ complex, newly made through double emulsification) for compounds containing phosphodiester or peptide bonds were studied. The results showed that PACC could hydrolyze organophosphorous pesticides not only in water but also in vegetable juice or tea extract. Hydrolysis rates of methamidophos, omethoate and chlorpyrifos in water are 32.39%, 27.12% and 46.62% respectively, those of chlorpyrifos and methamidophos in mung sprout juice 38.28% and 35.45% respectively, and that of chlorpyrifos in tea extract 59.76%. Hydrolysis rates of BSA (bovine serum albumin) in water and protein in tea extract by PACC increase by 54.30% and 86.46% respectively as compared with the control.

  11. Affinophoresis in two-dimensional agarose gel electrophoresis: specific separation of biomolecules by a moving affinity ligand.

    Science.gov (United States)

    Shimura, K; Kasai, K

    1987-02-15

    Affinophoresis is an electrophoretic separation technique for biomolecules which uses an affinophore. An affinophore is a macromolecular polyelectrolyte bearing affinity ligands. It migrates rapidly in an electric field, and consequently the electrophoretic mobility of molecules having affinity for the ligand is specifically changed. This technique has now been incorporated in two-dimensional agarose gel electrophoresis in a procedure which utilizes normal electrophoresis in the first dimension and affinophoresis in the second dimension. Proteins which do not have affinity for the ligand migrate to locations along a diagonal line passing through the origin, whereas proteins which have affinity are carried away from the line by the affinophore. Accordingly, molecules having affinity for the ligand can be readily assigned. Trypsins contained in Pronase and pancreatin were separated by this procedure using an affinophore bearing a competitive inhibitor for trypsin, benzamidine, on a polyanionic molecule (a polyacrylic acid derivative).

  12. Evaluation of the friction coefficient, the radial stress, and the damage work during needle insertions into agarose gels.

    Science.gov (United States)

    Urrea, Fabián A; Casanova, Fernando; Orozco, Gustavo A; García, José J

    2016-03-01

    Agarose hydrogels have been extensively used as a phantom material to mimic the mechanical behavior of soft biological tissues, e.g. in studies aimed to analyze needle insertions into the organs producing tissue damage. To better predict the radial stress and damage during needle insertions, this study was aimed to determine the friction coefficient between the material of commercial catheters and hydrogels. The friction coefficient, the tissue damage and the radial stress were evaluated at 0.2, 1.8, and 10mm/s velocities for 28, 30, and 32 gauge needles of outer diameters equal to 0.36, 0.31, and 0.23mm, respectively. Force measurements during needle insertions and retractions on agarose gel samples were used to analyze damage and radial stress. The static friction coefficient (0.295±0.056) was significantly higher than the dynamic (0.255±0.086). The static and dynamic friction coefficients were significantly smaller for the 0.2mm/s velocity compared to those for the other two velocities, and there was no significant difference between the friction coefficients for 1.8 and 10mm/s. Radial stress averages were 131.2±54.1, 248.3±64.2, and 804.9±164.3Pa for the insertion velocity of 0.2, 1.8, and 10mm/s, respectively. The radial stress presented a tendency to increase at higher insertion velocities and needle size, which is consistent with other studies. However, the damage work did not show to be a good predictor of tissue damage, which appears to be due to simplifications in the analytical model. Differently to other approaches, the method proposed here based on radial stress may be extended in future studies to quantity tissue damage in vivo along the entire needle track. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. A quality comparison of protein crystals grown under containerless conditions generated by diamagnetic levitation, silicone oil and agarose gel.

    Science.gov (United States)

    Cao, Hui-Ling; Sun, Li-Hua; Li, Jian; Tang, Lin; Lu, Hui-Meng; Guo, Yun-Zhu; He, Jin; Liu, Yong-Ming; Xie, Xu-Zhuo; Shen, He-Fang; Zhang, Chen-Yan; Guo, Wei-Hong; Huang, Lin-Jun; Shang, Peng; He, Jian-Hua; Yin, Da-Chuan

    2013-10-01

    High-quality crystals are key to obtaining accurate three-dimensional structures of proteins using X-ray diffraction techniques. However, obtaining such protein crystals is often a challenge. Several containerless crystallization techniques have been reported to have the ability to improve crystal quality, but it is unknown which is the most favourable way to grow high-quality protein crystals. In this paper, a quality comparison of protein crystals which were grown under three containerless conditions provided by diamagnetic levitation, silicone oil and agarose gel was conducted. A control experiment on a vessel wall was also simultaneously carried out. Seven different proteins were crystallized under the four conditions, and the crystal quality was assessed in terms of the resolution limit, the mosaicity and the Rmerge. It was found that the crystals grown under the three containerless conditions demonstrated better morphology than those of the control. X-ray diffraction data indicated that the quality of the crystals grown under the three containerless conditions was better than that of the control. Of the three containerless crystallization techniques, the diamagnetic levitation technique exhibited the best performance in enhancing crystal quality. This paper is to our knowledge the first report of improvement of crystal quality using a diamagnetic levitation technique. Crystals obtained from agarose gel demonstrated the second best improvement in crystal quality. The study indicated that the diamagnetic levitation technique is indeed a favourable method for growing high-quality protein crystals, and its utilization is thus potentially useful in practical efforts to obtain well diffracting protein crystals.

  14. Ergosterol purification from basidiomes of Clouded Agaric (Clitocybe nebularis (Fr. Kumm.

    Directory of Open Access Journals (Sweden)

    V. O. Antonyuk

    2014-08-01

    Full Text Available Ergosterol (ergosta-5 ,7,22-trien-3β-ol is a compound found only in fungi. Ergosterol has medical interest, as it is easily converted into Vitamin D2. In the previous work we have studied 22 species of true fungi. The highest quantity of ergosterol was found in basidiomes of Clouded Agaric (Clitocybe nebularis (Fr. Kumm. Meanwhile, there is no data on the purification of ergosterol from this fungus in the literature. The aim of research. The aim of research is to elaborate a rational method of obtaining ergosterol from basidiomes of Clouded Agaric and assess the perspectives of the raw material for its purification. Materials and methods. In order to choose the best method of ergosterol purification, it was obtained in two ways: 1 by alkaline hydrolisis that was used in the preparation of ergosterol from baker yeast and 2 by the extraction of raw matherial by methanol with following chromatography on silica gel. A substance with high ergosterol level was purified from marc basidiomes of Clouded Agaric by methanol extraction with following of freezing the methanol extract and the following chromatography on silica gel. This substance was dissolved in hexane and purified by chromatography on silica gel by washing the column sequentially with hexane, hexane - ethyl acetate (6:1 , hexane -ethyl acetate -methanol 4:2:1. The obtained fractions were dried and weighed. The analysis of the obtained compounds was carried out by gas-liquid сhromatography - mass spectrometry , Lieberman-Burchard reaction and TLC on silica gel. Chromatograms were spraied with saturated sodium antimony in chloroform. Results and discussion Pure ergosterol was obtained from dried baker's yeast and basidiomes marc of Clouded Agaric by alkaline hydrolysis followed by methylene chloride extraction of raw material and crystallization from ethanol and mixtures of benzene with ethanol (yield 0.71% and 0.52% . Methanol extraction of dried basidiomes marc of Clouded Agaric

  15. AgarTrap: a simplified Agrobacterium-mediated transformation method for sporelings of the liverwort Marchantia polymorpha L.

    Science.gov (United States)

    Tsuboyama, Shoko; Kodama, Yutaka

    2014-01-01

    The liverwort Marchantia polymorpha L. is being developed as an emerging model plant, and several transformation techniques were recently reported. Examples are biolistic- and Agrobacterium-mediated transformation methods. Here, we report a simplified method for Agrobacterium-mediated transformation of sporelings, and it is termed Agar-utilized Transformation with Pouring Solutions (AgarTrap). The procedure of the AgarTrap was carried out by simply exchanging appropriate solutions in a Petri dish, and completed within a week, successfully yielding sufficient numbers of independent transformants for molecular analysis (e.g. characterization of gene/protein function) in a single experiment. The AgarTrap method will promote future molecular biological study in M. polymorpha.

  16. In-house Manual Construction of High-Density and High-Quality Tissue Microarrays by Using Homemade Recipient Agarose-Paraffin Blocks.

    Science.gov (United States)

    Kim, Kyu Ho; Choi, Suk Jin; Choi, Yeon Il; Kim, Lucia; Park, In Suh; Han, Jee Young; Kim, Joon Mee; Chu, Young Chae

    2013-06-01

    Self-made tissue punches can be effectively used to punch holes in blank recipient paraffin blocks and extract tissue cores from the donor paraffin blocks for the low-cost construction of tissue microarrays (TMAs). However, variable degrees of section distortion and loss of the tissue cores can occurs during cutting of the TMAs, posing technical problems for in-house manual construction of high-density TMAs. We aimed to update the method for in-house manual TMA construction to improve the quality of high-density TMAs. Blocks of agarose gel were subjected to the standard tissue processing and embedding procedure to prepare recipient agarose-paraffin blocks. The self-made tissue punches and recipient agarose-paraffin blocks were used to construct TMAs, which were completely melted and re-embedded in paraffin to make finished TMA blocks. The donor tissue cores were completely integrated into the surrounding paraffin of the recipient blocks. This method enabled us to construct high-density TMAs with significantly less section distortion or loss of tissue cores during microtomy. Simple and inexpensive construction of high-density and high-quality TMAs can be warranted by using paraffinized agarose gels as recipient blocks.

  17. Quantification of DNA by Agarose Gel Electrophoresis and Analysis of the Topoisomers of Plasmid and M13 DNA Following Treatment with a Restriction Endonuclease or DNA Topoisomerase I

    Science.gov (United States)

    Tweedie, John W.; Stowell, Kathryn M.

    2005-01-01

    A two-session laboratory exercise for advanced undergraduate students in biochemistry and molecular biology is described. The first session introduces students to DNA quantification by ultraviolet absorbance and agarose gel electrophoresis followed by ethidium bromide staining. The second session involves treatment of various topological forms of…

  18. Cavitation-enhanced delivery of insulin in agar and porcine models of human skin

    Science.gov (United States)

    Feiszthuber, Helga; Bhatnagar, Sunali; Gyöngy, Miklós; Coussios, Constantin-C.

    2015-03-01

    Ultrasound-assisted transdermal insulin delivery offers a less painful and less invasive alternative to subcutaneous insulin injections. However, ultrasound-based drug delivery, otherwise known as sonophoresis, is a highly variable phenomenon, in part dependent on cavitation. The aim of the current work is to investigate the role of cavitation in transdermal insulin delivery. Fluorescently stained, soluble Actrapid insulin was placed on the surface of human skin-mimicking materials subjected to 265 kHz, 10% duty cycle focused ultrasound. A confocally and coaxially aligned 5 MHz broadband ultrasound transducer was used to detect cavitation. Two different skin models were used. The first model, 3% agar hydrogel, was insonated with a range of pressures (0.25-1.40 MPa peak rarefactional focal pressure—PRFP), with and without cavitation nuclei embedded within the agar at a concentration of 0.05% w/v. The second, porcine skin was insonated at 1.00 and 1.40 MPa PRFP. In both models, fluorescence measurements were used to determine penetration depth and concentration of delivered insulin. Results show that in agar gel, both insulin penetration depth and concentration only increased significantly in the presence of inertial cavitation, with up to a 40% enhancement. In porcine skin the amount of fluorescent insulin was higher in the epidermis of those samples that were exposed to ultrasound compared to the control samples, but there was no significant increase in penetration distance. The results underline the importance of instigating and monitoring inertial cavitation during transdermal insulin delivery.

  19. Big data analytics in hyperspectral imaging for detection of microbial colonies on agar plates (Conference Presentation)

    Science.gov (United States)

    Yoon, Seung-Chul; Park, Bosoon; Lawrence, Kurt C.

    2017-05-01

    Various types of optical imaging techniques measuring light reflectivity and scattering can detect microbial colonies of foodborne pathogens on agar plates. Until recently, these techniques were developed to provide solutions for hypothesis-driven studies, which focused on developing tools and batch/offline machine learning methods with well defined sets of data. These have relatively high accuracy and rapid response time because the tools and methods are often optimized for the collected data. However, they often need to be retrained or recalibrated when new untrained data and/or features are added. A big-data driven technique is more suitable for online learning of new/ambiguous samples and for mining unknown or hidden features. Although big data research in hyperspectral imaging is emerging in remote sensing and many tools and methods have been developed so far in many other applications such as bioinformatics, the tools and methods still need to be evaluated and adjusted in applications where the conventional batch machine learning algorithms were dominant. The primary objective of this study is to evaluate appropriate big data analytic tools and methods for online learning and mining of foodborne pathogens on agar plates. After the tools and methods are successfully identified, they will be applied to rapidly search big color and hyperspectral image data of microbial colonies collected over the past 5 years in house and find the most probable colony or a group of colonies in the collected big data. The meta-data, such as collection time and any unstructured data (e.g. comments), will also be analyzed and presented with output results. The expected results will be novel, big data-driven technology to correctly detect and recognize microbial colonies of various foodborne pathogens on agar plates.

  20. Cytotoxicity of dental alloys, metals, and ceramics assessed by millipore filter, agar overlay, and MTT tests.

    Science.gov (United States)

    Sjögren, G; Sletten, G; Dahl, J E

    2000-08-01

    Biocompatibility of dental materials is dependent on the release of elements from the materials. In addition, the composition, pretreatment, and handling of the materials influence the element release. This study evaluated the cytotoxicity of dental alloys, metals, and ceramics, with specific emphasis on the effects of altering the composition and the pretreatment. By using cells from a mouse fibroblast cell line and the agar overlay test, Millipore filter test, and MTT test, cytotoxicity of various metals, metal alloys, and ceramics for dental restoration were studied. Effects of altering the composition of a high noble gold alloy and of pretreatment of a ceramic-bonding alloy were also studied. In addition, the release of elements into the cell culture medium by the materials studied was measured using an inductively coupled plasma optical emission spectrophotometer. The results of the MTT test were analyzed statistically using ANOVA and Scheffé test at a significance level of P cytotoxic" according to the agar overlay and Millipore filter tests. For the MTT test, no significant differences were observed between these materials and controls, with the exception of JS C-gold and unalloyed titanium. The modified materials were ranked from "mildly cytotoxic" to "moderately cytotoxic" in the agar overlay and Millipore filter tests and from "noncytotoxic" to "moderately cytotoxic" in the MTT test. Thus, cytotoxicity was related to the alloy composition and treatment. The release of Cu and Zn seemed to be important for the cytotoxic effect. Alterations in the composition and the pretreatment can greatly influence the cytotoxicity, and the results stress the importance of carefully following the manufacturers' instructions when handling dental materials.

  1. Production of trichothecenes and other secondary metabolites by Fusarium culmorum and Fusarium equiseti on common laboratory media and a soil organic matter agar: An ecological interpretation

    DEFF Research Database (Denmark)

    Hestbjerg, H.; Nielsen, Kristian Fog; Thrane, Ulf

    2002-01-01

    trichothecene production was detected for 94 of 102 F culmorum isolates, only 8 of 57 F equiseti isolates were positive. Profiles of secondary metabolites were compared by following growth on yeast extract sucrose agar (YES), potato sucrose agar (PSA), and an agar medium, prepared from soil organic matter (SOM...

  2. Cytotoxicity of ferrite particles by MTT and agar diffusion methods for hyperthermic application

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong-Hyun [Brain Korea 21 Project for Medical Science, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Lee, Se-Ho [Brain Korea 21 Project for Medical Science, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Kim, Kyoung-Nam [Brain Korea 21 Project for Medical Science, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Kim, Kwang-Mahn [Brain Korea 21 Project for Medical Science, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Shim, In-Bo [Department of Electronic Physics, Kookmin University, Seoul 136-702 (Korea, Republic of); Lee, Yong-Keun [Brain Korea 21 Project for Medical Science, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of) and Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of)]. E-mail: leeyk@yumc.yonsei.ac.kr

    2005-05-15

    We investigated the cytotoxicity of the prepared various ferrites (Fe-, Li-, Ni/Zn/Cu-, Ba-, Sr-, Co-, Co/Ni-ferrites) using MTT assay as well as agar diffusion method. Their cytotoxicity was compared with that of alginate-encapsulated ferrites. In the MTT assay, Fe{sub 3}O{sub 4} and SrFe{sub 12}O{sub 19} ferrite showed the highest cell viability of 90%. Alginate-encapsulated Ba-ferrite was ranked mildly cytotoxic, whereas their ferrite particles were ranked cytotoxic.

  3. Potato carrot agar with manganese as an isolation medium for Alternaria, Epicoccum and Phoma

    DEFF Research Database (Denmark)

    Sørensen, Jens Laurids; Mogensen, Jesper Mølgaard; Thrane, Ulf

    2009-01-01

    A semi-selective medium for isolation of Alternaria spp., Epicoccum sp. and Phoma spp. from soil and plant samples was developed. The basal medium was a modified potato carrot agar (PCA), containing 10 g/L of potato and carrot. It is known that the target genera sporulate well on standard PCA when...... samples and eight grain samples were examined using PCA-Mn and three commonly used isolation media, DRYES, DG18 and V8. On the three conventional media growth of several genera was observed with the predominant being Aspergillus, Eurotium. Fusarium. Mucor. Penicillium and Rhizopus. Of these only F...

  4. Diagnostic Value of Processing Cytologic Aspirates of Renal Tumors in Agar Cell (Tissue) Blocks

    DEFF Research Database (Denmark)

    Smedts, F.; Schrik, M.; Horn, T.

    2010-01-01

    Objective To adapt a method enabling utilization of most of the harvest from a fine needle aspirate in an effort to improve diagnostic accuracy in the assessment of a renal tumor in a single histologic slide. Study Design In a series of 43 renal tumors, 2 fine needle aspirations were performed, 4...... smears were prepared after each aspiration for conventional cytology and the remaining aspirate was processed for the improved agar microbiopsy (AM) method. Conventional cytology slides, AM slides and surgical specimens were diagnosed separately, after which the diagnoses were compared...

  5. The bactericidal effect of carbon nanotube/agar composites irradiated with near-infrared light on Streptococcus mutans

    OpenAIRE

    Akasaka, Tsukasa; Matsuoka, Makoto; Hashimoto, Takeshi; Abe, Shigeaki; Uo, Motohiro; Watari, Fumio

    2010-01-01

    Dental caries are mainly associated with oral pathogens, and Streptococcus 2 mutans is a primary cariogenic organism. Many methods have been established to eliminate S. mutans from the oral cavity. This study aimed to evaluate the effect of carbon nanotube (CNT)/agar composites irradiated with near-infrared (NIR) light on S. mutans, as a potential photothermal antimicrobial nanotherapy. A colony-forming unit assay clearly showed that CNT/agar composites attain bactericidal activity after NIR ...

  6. Effets des différents doses d'agar du milieu de culture sur l'induction ...

    African Journals Online (AJOL)

    Cette étude constitue une alternative à la propagation du bananier qui se fait par rejetonnage, caractérisé par la difficulté de trouver un grand nombre de rejets lors de l'installation d'un premier champ. Mots clés : Explants, milieu de culture, agar, bananier, FHIA-01, rhizogénèse. Effects of different doses of agar culture ...

  7. Development of a More Sensitive and Specific Chromogenic Agar Medium for the Detection of Vibrio parahaemolyticus and Other Vibrio Species.

    Science.gov (United States)

    Yeung, Marie; Thorsen, Trevor

    2016-11-08

    Foodborne infections in the US caused by Vibrio species have shown an upward trend. In the genus Vibrio, V. parahaemolyticus is responsible for the majority of Vibrio-associated infections. Thus, accurate differentiation among Vibrio spp. and detection of V. parahaemolyticus is critically important to ensure the safety of our food supply. Although molecular techniques are increasingly common, culture-depending methods are still routinely done and they are considered standard methods in certain circumstances. Hence, a novel chromogenic agar medium was tested with the goal of providing a better method for isolation and differentiation of clinically relevant Vibrio spp. The protocol compared the sensitivity, specificity and detection limit for the detection of V. parahaemolyticus between the new chromogenic medium and a conventional medium. Various V. parahaemolyticus strains (n=22) representing diverse serotypes and source of origins were used. They were previously identified by Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC), and further verified in our laboratory by tlh-PCR. In at least four separate trials, these strains were inoculated on the chromogenic agar and thiosulfate-citrate-bile salts-sucrose (TCBS) agar, which is the recommended medium for culturing this species, followed by incubation at 35-37 °C for 24-96 hr. Three V. parahaemolyticus strains (13.6%) did not grow optimally on TCBS, nonetheless exhibited green colonies if there was growth. Two strains (9.1%) did not yield the expected cyan colonies on the chromogenic agar. Non-V. parahaemolyticus strains (n=32) were also tested to determine the specificity of the chromogenic agar. Among these strains, 31 did not grow or exhibited other colony morphologies. The mean recovery of V. parahaemolyticus on the chromogenic agar was ~96.4% relative to tryptic soy agar supplemented with 2% NaCl. In conclusion, the new chromogenic agar is an effective medium to detect V

  8. High resolution images of resin structure in Agar wood by means of SEM and MICRO-CT

    International Nuclear Information System (INIS)

    Khairiah Yazid; Roslan Yahya; Nadira Kamarudin; Mohd Zaid Abdullah; Mohd Ashhar Khalid; Abdul Aziz Mohamed

    2012-01-01

    Detection and analysis of resin is particularly significant since the commercial value of agar wood is related to the quantity of resins that are present. This articles explores the potential of a scanning electron microscope in combination with new non-destructive 3D visualization technique, X-ray micro-computed tomography, as imaging tools to visualize micro-structure resin in agar wood. These techniques were used to compare two samples of agar wood chips: high grade and low grade. From the results, it can be concluded that a wood cell filled with resin deposit have a higher attenuation. It can be shown that the combination of scanning electron microscopy and micro-CT can offer high resolution images concerning the localization and structure of resin inside Agar wood. while the second allows the 3D investigation of internal structure of agar wood, the first technique can provide details 2D morphological information. These imaging techniques, although sophisticated can be used for standard development especially in grading og agar wood for commercial activities. (author)

  9. Biofilm Removal and Antimicrobial Activities of Agar Hydrogel Containing Colloid Nano-Silver against Staphylococcus aureus and Salmonella typhimurium

    Directory of Open Access Journals (Sweden)

    Leyla Sadat Bouryabaf

    2017-10-01

    Full Text Available Background:    Antibacterial and biofilm removal effects of agar hydrogel incorporating silver nanoparticles (SNP at various concentrations were studied against Staphylococcus aureus and Salmonella typhimurium in vitro.Methods:      The minimum inhibitory concentrations (MIC of SNP was determined by agar dilution method. Then, hydrogels were prepared by mixing of 0.5% w/v agar and SNP (1/2 MIC, MIC, and 2 MIC and their inhibitory efficacies against planktonic and biofilm forms of bacteria were measured using agar spot and microtiter test, respectively.Results:    The MIC value was 125 µg/ mL for both bacteria. All SNP hydrogels represented antibacterial activity against Staphylococcus aureus and S. typhimurium on agar culture, which was significant compared to control group (silver sulfadiazine cream. The developed biofilm of S. aureus and S. typhimurium were strongly (85% reduction and modernly affected (60% reduction by SNP hydrogels during 15 min contact time, respectively. A dose-dependent biofilm reduction was not demonstrated when different SNP concentrations were tested. Moreover, the results from this study confirmed the moderate sanitizing ability of SNP loaded hydrogel against planktonic forms of both bacteria, which SNP (2MIC hydrogel decreased only 2.3 log10 CFU/ mL in a primary population of S. typhimurium during 15 min exposure time.Conclusion:     We recommended SNP incorporated agar hydrogel as an effective biofilm removal sanitizer.

  10. Comparison of manual mycobacteria growth indicator tube and epsilometer test with agar proportion method for susceptibility testing of Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    N Karabulut

    2014-01-01

    Full Text Available Background and Objectives: Antimycobacterial susceptibility tests take weeks, and delayed therapy can lead to spread of Mycobacterium tuberculosis. Therefore, rapid, accurate and cost-effective methods are required for proper therapy selection. In this study, the Mycobacteria growth indicator tube (MGIT and epsilometer test (Etest methods were compared to the agar proportion method for susceptibility testing of Mycobacterium tuberculosis. Materials and Methods: The susceptibility tests against isoniazid (INH, rifampin (RIF, streptomycin (STM and ethambutol (ETM of 51 M. tuberculosis complex isolates were analyzed by the MGIT, Etest and agar proportion methods. Results: The concordance between MGIT/Etest and agar proportion methods was 98% for INH and 100% for RIF, STM, ETM. There were not statistically significant differences in results of the susceptibility tests between MGIT/Etest and the reference agar proportion method. Conclusion: The results have shown that MGIT and Etest methods can be used instead of the agar proportion method, because these two methods are more rapid and easier than the agar proportion method.

  11. An agar gel membrane-PDMS hybrid microfluidic device for long term single cell dynamic study.

    Science.gov (United States)

    Wong, Ieong; Atsumi, Shota; Huang, Wei-Chih; Wu, Tung-Yun; Hanai, Taizo; Lam, Miu-Ling; Tang, Ping; Yang, Jian; Liao, James C; Ho, Chih-Ming

    2010-10-21

    Significance of single cell measurements stems from the substantial temporal fluctuations and cell-cell variability possessed by individual cells. A major difficulty in monitoring surface non-adherent cells such as bacteria and yeast is that these cells tend to aggregate into clumps during growth, obstructing the tracking or identification of single-cells over long time periods. Here, we developed a microfluidic platform for long term single-cell tracking and cultivation with continuous media refreshing and dynamic chemical perturbation capability. The design highlights a simple device-assembly process between PDMS microchannel and agar membrane through conformal contact, and can be easily adapted by microbiologists for their routine laboratory use. The device confines cell growth in monolayer between an agar membrane and a glass surface. Efficient nutrient diffusion through the membrane and reliable temperature maintenance provide optimal growth condition for the cells, which exhibited fast exponential growth and constant distribution of cell sizes. More than 24 h of single-cell tracking was demonstrated on a transcription-metabolism integrated synthetic biological model, the gene-metabolic oscillator. Single cell morphology study under alcohol toxicity allowed us to discover and characterize cell filamentation exhibited by different E. coli isobutanol tolerant strains. We believe this novel device will bring new capabilities to quantitative microbiology, providing a versatile platform for single cell dynamic studies.

  12. Mechanical response of agar gel irradiated with Nd:YAG nanosecond laser pulses

    Science.gov (United States)

    Pérez-Gutiérrez, Francisco G.; Evans, Rodger; Camacho-López, Santiago; Aguilar, Guillermo

    2010-02-01

    Nanosecond long laser pulses are used in medical applications where precise tissue ablation with minimal thermal and mechanical collateral damage is required. When a laser pulse is incident on a material, optical energy will be absorbed by a combination of linear and nonlinear absorption according to both: laser light intensity and material properties. In the case of water or gels, the first results in heat generation and thermoelastic expansion; while the second results in an expanding plasma formation that launches a shock wave and a cavitation/boiling bubble. Plasma formation due to nonlinear absorption of nanosecond laser pulses is originated by a combination of multiphoton ionization and thermionic emission of free electrons, which is enhanced when the material has high linear absorption coefficient. In this work, we present measurements of pressure transients originated when 6 ns laser pulses are incident on agar gels with varying linear absorption coefficient, mechanical properties and irradiation geometry using laser radiant exposures above threshold for bubble formation. The underlying hypothesis is that pressure transients are composed of the superposition of both: shock wave originated by hot expanding plasma resulting from nonlinear absorption of optical energy and, thermoelastic expansion originated by heat generation due to linear absorption of optical energy. The objective of this work is to evaluate the relative contribution of each absorption mechanism to mechanical effects in agar gel. Real time pressure transients are recorded with PVDF piezoelectric sensors and time-resilved imaging from 50 μm to 10 mm away from focal point.

  13. Measurement of hemoglobin A1 by liquid chromatography and by agar gel electrophoresis compared.

    Science.gov (United States)

    Hayes, E J; Gleason, R E; Soeldner, J S; Wacks, M; Blankstein, L

    1981-03-01

    We compare measurement of total fast hemoglobin (HbA1) by "high-performance" liquid chromatography and by electrophoresis on agar gel. Blood samples were obtained from a diverse population (n = 222): offspring of two diabetic parents, diabetic patients with and without retinopathy, diabetic and non-diabetic pregnant women, patients in the coronary-care unit, and normal persons. Precision studies with a normal and an above-normal A1 sample resulted in overall CVs of 9.0% and 4.6% for the electrophoretic method and 4.4% and 2% for the chromatographic method. Linear regression analysis of values for total fast hemoglobin for the complete sample population and for each subgroup showed results of the electrophoretic method to be in excellent agreement with those by the chromatographic method. We conclude that the agar gel electrophoretic method offers a reproducible means for HbA1 determination that is comparable to the HPLC method in terms of accuracy and is highly suited for routine laboratory use.

  14. Mitis salivarius-bacitracin 10% sacarose agar for oral streptococci and Streptococcus mutans counts.

    Science.gov (United States)

    Gutiérrez de Annan, S; Ruíz de Valladares, R E; Benito de Cárdenas, I L

    1997-01-01

    The MSB Agar (mitis salivarius-bacitracin) 20% sacarose medium is frequently used for the isolation and count of total streptococci and Streptococcus mutans. Although it is considered a selective culture medium for this micro-organism, S. mutans recovery in this medium is much lower than in this Mitis Salivarius Agar (MSA). Because the number of S. mutans in saliva is used for estimating caries risk and activity from a microbiological stand point, the aim of this work was to find a modification of the MSB 20% sacarose medium so that it would offer not only selectivity in the isolation but also maximum recovery. This would detect people at risk more efficiency and would evaluate the preventive odontological treatments more accurately. The results show that: 1) the greatest recovery of total streptococci and S. mutans is obtained in the MSB 10% sacarose medium, 2) S. mutans must be incubated in aerobiosis and the total streptococci in a candle jar (10% CO2). MSB 10% sacarose medium is proposed as a choice medium for the microbiological estimation of cariogenic risk and activity, to detect infection levels and evaluate preventive odontological treatments.

  15. Evaluation of a modified Cefsulodin-Irgasan-Novobiocin agar for isolation of Yersinia spp.

    Directory of Open Access Journals (Sweden)

    Lai Kuan Tan

    Full Text Available Y. enterocolitica and Y. pseudotuberculosis are important food borne pathogens. However, the presence of competitive microbiota makes the isolation of Y. enterocolitica and Y. pseudotuberculosis from naturally contaminated foods difficult. We attempted to evaluate the performance of a modified Cefsulodin-Irgasan-Novobiocin (CIN agar in the differentiation of Y. enterocolitica from non-Yersinia species, particularly the natural intestinal microbiota. The modified CIN enabled the growth of Y. enterocolitica colonies with the same efficiency as CIN and Luria-Bertani agar. The detection limits of the modified CIN for Y. enterocolitica in culture medium (10 cfu/ml and in artificially contaminated pork (10(4 cfu/ml were also comparable to those of CIN. However, the modified CIN provided a better discrimination of Yersinia colonies from other bacteria exhibiting Yersinia-like colonies on CIN (H2S-producing Citrobacter freundii, C. braakii, Enterobacter cloacae, Aeromonas hydrophila, Providencia rettgeri, and Morganella morganii. The modified CIN exhibited a higher recovery rate of Y. enterocolitica from artificially prepared bacterial cultures and naturally contaminated samples compared with CIN. Our results thus demonstrated that the use of modified CIN may be a valuable means to increase the recovery rate of food borne Yersinia from natural samples, which are usually contaminated by multiple types of bacteria.

  16. Characterization of internal structure of hydrated agar and gelatin matrices by cryo-SEM

    KAUST Repository

    Rahbani, Janane

    2012-12-26

    There has been a considerable interest in recent years in developing polymer gel matrices for many important applications such as 2DE for quantization and separation of a variety of proteins and drug delivery system to control the release of active agents. However, a well-defined knowledge of the ultrastructures of the gels has been elusive. In this study, we report the characterization of two different polymers used in 2DE: Gelatin, a naturally occurring polymer derived from collagen (protein) and agar, a polymer of polysaccharide (sugar) origin. Low-temperature SEM is used to examine the internal structure of these gels in their frozen natural hydrated states. Results of this study show that both polymers have an array of hollow cells that resembles honeycomb structures. While agar pores are almost circular, the corresponding Gaussian curve is very broad exhibiting a range of radii from nearly 370 to 700 nm. Gelatin pores are smaller and more homogeneous reflecting a narrower distribution from nearly 320 to 650 nm. Overall, these ultrastructural findings could be used to correlate with functions of the polymers. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Mechanical and water barrier properties of agar/κ-carrageenan/konjac glucomannan ternary blend biohydrogel films.

    Science.gov (United States)

    Rhim, Jong-Whan; Wang, Long-Feng

    2013-07-01

    Multicomponent hydrogel films composed of agar, κ-carrageenan, konjac glucomannan powder, and nanoclay (Cloisite(®) 30B) were prepared and their mechanical and water barrier properties such as water vapor permeability (WVP), water contact angle (CA), water solubility (WS), water uptake ratio (WUR), water vapor uptake ratio (WVUR) were determined. Mechanical, water vapor barrier, and water resistance properties of the ternary blend film exhibited middle range of individual component films, however, they increased significantly after formation of nanocomposite with the clay. Especially, the water holding capacity of the ternary blend biopolymer films increased tremendously, from 800% to 1681% of WUR for agar and κ-carrageenan films up to 5118% and 5488% of WUR for the ternary blend and ternary blend nanocomposite films, respectively. Water vapor adsorption behavior of films was also tested by water vapor adsorption kinetics and water vapor adsorption isotherms test. Preliminary test result for fresh spinach packaging revealed that the ternary blend biohydrogel films had a high potential for the use as an antifogging film for packaging highly respiring agricultural produce. In addition, the ternary blend nanocomposite film showed an antimicrobial activity against Gram-positive bacteria, Listeria monocytogenes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Visualization of Biosurfactant Film Flow in a Bacillus subtilis Swarm Colony on an Agar Plate.

    Science.gov (United States)

    Kim, Kyunghoon; Kim, Jung Kyung

    2015-08-26

    Collective bacterial dynamics plays a crucial role in colony development. Although many research groups have studied the behavior of fluidic swarm colonies, the detailed mechanics of its motion remains elusive. Here, we developed a visualization method using submicron fluorescent beads for investigating the flow field in a thin layer of fluid that covers a Bacillus subtilis swarm colony growing on an agar plate. The beads were initially embedded in the agar plate and subsequently distributed spontaneously at the upper surface of the expanding colony. We conducted long-term live cell imaging of the B. subtilis colony using the fluorescent tracers, and obtained high-resolution velocity maps of microscale vortices in the swarm colony using particle image velocimetry. A distinct periodic fluctuation in the average speed and vorticity of flow in swarm colony was observed at the inner region of the colony, and correlated with the switch between bacterial swarming and growth phases. At the advancing edge of the colony, both the magnitudes of velocity and vorticity of flow in swarm colony were inversely correlated with the spreading speed of the swarm edge. The advanced imaging tool developed in this study would facilitate further understanding of the effect of micro vortices in swarm colony on the collective dynamics of bacteria.

  19. Visualization of Biosurfactant Film Flow in a Bacillus subtilis Swarm Colony on an Agar Plate

    Directory of Open Access Journals (Sweden)

    Kyunghoon Kim

    2015-08-01

    Full Text Available Collective bacterial dynamics plays a crucial role in colony development. Although many research groups have studied the behavior of fluidic swarm colonies, the detailed mechanics of its motion remains elusive. Here, we developed a visualization method using submicron fluorescent beads for investigating the flow field in a thin layer of fluid that covers a Bacillus subtilis swarm colony growing on an agar plate. The beads were initially embedded in the agar plate and subsequently distributed spontaneously at the upper surface of the expanding colony. We conducted long-term live cell imaging of the B. subtilis colony using the fluorescent tracers, and obtained high-resolution velocity maps of microscale vortices in the swarm colony using particle image velocimetry. A distinct periodic fluctuation in the average speed and vorticity of flow in swarm colony was observed at the inner region of the colony, and correlated with the switch between bacterial swarming and growth phases. At the advancing edge of the colony, both the magnitudes of velocity and vorticity of flow in swarm colony were inversely correlated with the spreading speed of the swarm edge. The advanced imaging tool developed in this study would facilitate further understanding of the effect of micro vortices in swarm colony on the collective dynamics of bacteria.

  20. An electrochemical approach to monitor pH change in agar media during plant tissue culture.

    Science.gov (United States)

    Wang, Min; Ha, Yang

    2007-05-15

    In this work, metal oxide microelectrodes were developed to monitor pH change in agar media during plant tissue culture. An antimony wire was produced by a new approach "capillary melt method". The surface of the obtained antimony wire was oxidized in a potassium nitrate melt to fabricate an antimony oxide film for pH sensing. Characterization results show that the oxide layer grown on the wire surface consists of Sb(2)O(3) crystal phase. The sensing response, open-circuit potential, of the electrode has a good linear relationship (R(2)=1.00) with pH value of the test solution. Adding organic compounds into the test media would not affect the linear relationship, although the slope of the lines varied with different ingredients added. The antimony oxide electrodes were employed to continuously monitor pH change of agar culture media during a 2-week plant tissue culture of Dendrobium candidum. The antimony oxide electrode fabricated this way has the advantages of low cost, easy fabrication, fast response, and almost no contamination introduced into the system. It would be suitable for in situ and continuous pH measurement in many bio applications.

  1. Characterization of internal structure of hydrated agar and gelatin matrices by cryo-SEM.

    Science.gov (United States)

    Rahbani, Janane; Behzad, Ali R; Khashab, Niveen M; Al-Ghoul, Mazen

    2013-02-01

    There has been a considerable interest in recent years in developing polymer gel matrices for many important applications such as 2DE for quantization and separation of a variety of proteins and drug delivery system to control the release of active agents. However, a well-defined knowledge of the ultrastructures of the gels has been elusive. In this study, we report the characterization of two different polymers used in 2DE: Gelatin, a naturally occurring polymer derived from collagen (protein) and agar, a polymer of polysaccharide (sugar) origin. Low-temperature SEM is used to examine the internal structure of these gels in their frozen natural hydrated states. Results of this study show that both polymers have an array of hollow cells that resembles honeycomb structures. While agar pores are almost circular, the corresponding Gaussian curve is very broad exhibiting a range of radii from nearly 370 to 700 nm. Gelatin pores are smaller and more homogeneous reflecting a narrower distribution from nearly 320 to 650 nm. Overall, these ultrastructural findings could be used to correlate with functions of the polymers. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Evaluation of a Modified Cefsulodin-Irgasan-Novobiocin Agar for Isolation of Yersinia spp

    Science.gov (United States)

    Tan, Lai Kuan; Ooi, Peck Toung; Carniel, Elisabeth; Thong, Kwai Lin

    2014-01-01

    Y. enterocolitica and Y. pseudotuberculosis are important food borne pathogens. However, the presence of competitive microbiota makes the isolation of Y. enterocolitica and Y. pseudotuberculosis from naturally contaminated foods difficult. We attempted to evaluate the performance of a modified Cefsulodin-Irgasan-Novobiocin (CIN) agar in the differentiation of Y. enterocolitica from non-Yersinia species, particularly the natural intestinal microbiota. The modified CIN enabled the growth of Y. enterocolitica colonies with the same efficiency as CIN and Luria-Bertani agar. The detection limits of the modified CIN for Y. enterocolitica in culture medium (10 cfu/ml) and in artificially contaminated pork (104 cfu/ml) were also comparable to those of CIN. However, the modified CIN provided a better discrimination of Yersinia colonies from other bacteria exhibiting Yersinia-like colonies on CIN (H2S-producing Citrobacter freundii, C. braakii, Enterobacter cloacae, Aeromonas hydrophila, Providencia rettgeri, and Morganella morganii). The modified CIN exhibited a higher recovery rate of Y. enterocolitica from artificially prepared bacterial cultures and naturally contaminated samples compared with CIN. Our results thus demonstrated that the use of modified CIN may be a valuable means to increase the recovery rate of food borne Yersinia from natural samples, which are usually contaminated by multiple types of bacteria. PMID:25170941

  3. Roughness-controlled self-assembly of mannitol/LB agar microparticles by polymorphic transformation for pulmonary drug delivery.

    Science.gov (United States)

    Zhang, Fengying; Ngoc, Nguyen Thi Quynh; Tay, Bao Hui; Mendyk, Aleksander; Shao, Yu-Hsuan; Lau, Raymond

    2015-01-05

    Novel roughness-controlled mannitol/LB Agar microparticles were synthesized by polymorphic transformation and self-assembly method using hexane as the polymorphic transformation reagent and spray-dried mannitol/LB Agar microparticles as the starting material. As-prepared microparticles were characterized by Fourier transform infrared spectra (FTIR), X-ray diffraction spectra (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and Andersen Cascade Impactor (ACI). The XRD and DSC results indicate that after immersing spray-dried mannitol/LB Agar microparticles in hexane, β-mannitol was completely transformed to α-mannitol in 1 h, and all the δ-mannitol was transformed to α form after 14 days. SEM shows that during the transformation the nanobelts on the spray-dried mannitol/LB Agar microparticles become more dispersed and the contour of the individual nanobelts becomes more noticeable. Afterward, the nanobelts self-assemble to nanorods and result in rod-covered mannitol/LB Agar microparticles. FTIR indicates new hydrogen bonds were formed among mannitol, LB Agar, and hexane. SEM images coupled with image analysis software reveal that different surface morphology of the microparticles have different drug adhesion mechanisms. Comparison of ACI results and image analysis of SEM images shows that an increase in the particle surface roughness can increase the fine particle fractions (FPFs) using the rod-covered mannitol microparticles as drug carriers. Transformed microparticles show higher FPFs than commercially available lactose carriers. An FPF of 28.6 ± 2.4% was achieved by microparticles transformed from spray-dried microparticles using 2% mannitol(w/v)/LB Agar as feed solution. It is comparable to the highest FPF reported in the literature using lactose and spray-dried mannitol as carriers.

  4. The evaluation of susceptibility of clinical and environmental Nontuberculosis mycobacterium isolated from Isfahan to Ciprofloxacin by Agar dilution method

    Directory of Open Access Journals (Sweden)

    Tooba Radaei

    2013-01-01

    Full Text Available Introduction: Ciprofloxacin is a fluoroquinolone antibiotic which is active against mycobacteria and functions by inhibiting DNA gyrase and topoisomerase IV enzymes. Resistance to ciprofloxacin and other fluoroquinolones may evolve rapidly, even during a course of treatment. Nowadays, mycobacteria exhibit resistance worldwide and usage of the fluoroquinolones, particularly in nontuberculous mycobacteria disease, has complicated the related treatments. Materials and methods: A total of 39 clinical and environmental isolates of NTM from microbial collections of Isfahan Microbiology Department and Tuberculosis center were obtained. The isolates were investigated by primary conventional methods consisting of colony characteristics, pigmentation, growth temperature, rate of growth and Ziehl–Neelsen staining. The susceptibility of isolates to the concentrations of 1, 2 and 4 µg/ml of ciprofloxacin was determined by agar dilution method according to the CLSI guideline.Results: Thirty nine isolates were identified by phenotypic tests. The frequency of isolates was as follow: M. fortuitum; 25 cases, M. gordonae; 10 cases, M. smegmatis; 1 case, M.‏conceptionense; 1 case and M. abscessus; 2 cases. All isolates except Mycobacterium abscessus were sensitive to all three concentrations of 1, 2 and 4 µg/ml ciprofloxacin.Discussion and conclusion: Due to the sensitivity of environmental nontuberculous mycobacteria isolates (except M. abscessus and clinical isolates including M. fortuitum and M.‏gordonae to ciprofloxacin, this antibiotic could be regarded as the original drug in the treatment of these infections.

  5. Colonyzer: automated quantification of micro-organism growth characteristics on solid agar

    Directory of Open Access Journals (Sweden)

    Young Alexander

    2010-05-01

    Full Text Available Abstract Background High-throughput screens comparing growth rates of arrays of distinct micro-organism cultures on solid agar are useful, rapid methods of quantifying genetic interactions. Growth rate is an informative phenotype which can be estimated by measuring cell densities at one or more times after inoculation. Precise estimates can be made by inoculating cultures onto agar and capturing cell density frequently by plate-scanning or photography, especially throughout the exponential growth phase, and summarising growth with a simple dynamic model (e.g. the logistic growth model. In order to parametrize such a model, a robust image analysis tool capable of capturing a wide range of cell densities from plate photographs is required. Results Colonyzer is a collection of image analysis algorithms for automatic quantification of the size, granularity, colour and location of micro-organism cultures grown on solid agar. Colonyzer is uniquely sensitive to extremely low cell densities photographed after dilute liquid culture inoculation (spotting due to image segmentation using a mixed Gaussian model for plate-wide thresholding based on pixel intensity. Colonyzer is robust to slight experimental imperfections and corrects for lighting gradients which would otherwise introduce spatial bias to cell density estimates without the need for imaging dummy plates. Colonyzer is general enough to quantify cultures growing in any rectangular array format, either growing after pinning with a dense inoculum or growing with the irregular morphology characteristic of spotted cultures. Colonyzer was developed using the open source packages: Python, RPy and the Python Imaging Library and its source code and documentation are available on SourceForge under GNU General Public License. Colonyzer is adaptable to suit specific requirements: e.g. automatic detection of cultures at irregular locations on streaked plates for robotic picking, or decreasing analysis time by

  6. Agar hydrogel with silver nanoparticles to prolong the shelf life of Fior di Latte cheese.

    Science.gov (United States)

    Incoronato, A L; Conte, A; Buonocore, G G; Del Nobile, M A

    2011-04-01

    The objective of this work was to evaluate the effectiveness of an antimicrobial packaging system containing active nanoparticles on the quality deterioration of Fior di Latte cheese. To this aim, 3 concentrations of silver montmorillonite embedded in agar were used. The cell loads of spoilage and useful microorganisms were monitored during a refrigerated storage period. Moreover, cheese sensory quality (i.e., odor, color, consistency, and overall quality) was evaluated by means of a panel test. Results showed that the active packaging system markedly increased the shelf life of Fior di Latte cheese, due to the ability of silver cations to control microbial proliferation, without affecting the functional dairy microbiota and the sensory characteristics of the product. The active packaging system developed in this work could be used to prolong the shelf life of Fior di Latte and boost its distribution beyond local market borders. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  7. Antimicrobial Disk Susceptibility Testing of Leptospira spp. Using Leptospira Vanaporn Wuthiekanun (LVW) Agar.

    Science.gov (United States)

    Wuthiekanun, Vanaporn; Amornchai, Premjit; Langla, Sayan; White, Nicholas J; Day, Nicholas P J; Limmathurotsakul, Direk; Peacock, Sharon J

    2015-08-01

    Leptospira Vanaporn Wuthiekanun (LVW) agar was used to develop a disk diffusion assay for Leptospira spp. Ten pathogenic Leptospira isolates were tested, all of which were susceptible to 17 antimicrobial agents (amoxicillin/clavulanic acid, amoxicillin, azithromycin, cefoxitin, ceftazidime, ceftriaxone, chloramphenicol, ciprofloxacin, clindamycin, doripenem, doxycycline, gentamicin, linezolid, nitrofurantoin, penicillin, piperacillin/tazobactam, and tetracycline). All 10 isolates had no zone of growth inhibition for four antimicrobials (fosfomycin, nalidixic acid, rifampicin, and trimethoprim/sulfamethoxazole). Of the ten Leptospira, seven had a growth inhibition zone of ≤ 21 mm for aztreonam, the zone diameter susceptibility break point for Enterobacteriaceae. This assay could find utility as a simple screening method during the epidemiological surveillance of antimicrobial resistance in Leptospira spp. © The American Society of Tropical Medicine and Hygiene.

  8. Estradiol receptors in the pituitary and anterior hypothalamus of the rat: measurement by agar gel electrophoresis.

    Science.gov (United States)

    Davies, I J; Naftolin, F; Ryan, K J; Siu, J

    1975-05-01

    The reliability of agar gel electrophoresis in the measurement of high-affinity saturable estrogen-binding component in the cytosol of the rat pituitary gland and anterior hypothalamus was assessed. The available binding sites were determined in small samples with good precision and accuracy. Incubation with 100-fold competitor was more satisfactory than heat-treatment for measuring nonspecific binding. There was substantial, but incomplete, dissociation of albumin-estradiol complexes. The total number of estrogen binding sites in the anterior hypothalamus was approximately 15% greater in 28-day-old females than males (p .02). However, differences in the number of binding sites in the pituitary was not significant (p .02). The pituitary was found to contain twice as many binding sites as the anterior hypothalamus in both sexes. The latter finding is consistent with the importance of the direct action of estrogen on the pituitary in mediating pituitary function.

  9. Optimasi Waktu Proses Hidrolisis dan Fermentasi dalam Produksi Bioetanol dari Limbah Pengolahan Agar (Gracilaria sp. Industri

    Directory of Open Access Journals (Sweden)

    Rodiah Nurbaya Sari

    2013-12-01

    menggunakan kapang Trichoderma viride dan khamir Saccharomyces cerevisiae. Penelitian yang dilakukan terdiri dari beberapa tahap yaitu karakterisasi limbah agar industri, hidrolisis enzimatis menggunakan kapang Trichoderma viride penghasil selulase, dan fermentasi dengan khamir Saccharomyces cerevisiae. Hasilnya menunjukkan bahwa waktu optimal untuk hidrolisis enzimatis adalah 4 hari pada suhu 28 oC dan pH 3,91; aktivitas CMCase 210,48 IU/ml dan menghasilkan total gula pereduksi 6,74 mg/ml. Sedangkan untuk waktu fermentasi yang optimal adalah 2 hari pada suhu 32 oC dan pH 4,66 dengan nilai OD 600 nm 0,0181 menghasilkan etanol kasar dengan kadar 0,47% (b/b.

  10. Phenotypic differentiation of species from Aspergillus section Flavi on neutral red desiccated coconut agar

    DEFF Research Database (Denmark)

    Atanda, O. O.; Adetunji, M. C.; Ezekiel, C. N.

    2014-01-01

    In order to facilitate easy and rapid identification of aflatoxin-producing Aspergillus species, the phenotypic traits of Aspergillus section Flavi isolates were examined on neutral red desiccated coconut agar (NRDCA). Phenotype variations in colony morphology and the relationship between colour...... supported morphological differentiation of the four species based on colony features, conidia type and colour. In particular, the two very closely related minisclerotial species, A. minisclerotigenes and A. parvisclerotigenus, were clearly differentiated by their colony colour on NRDCA. All toxigenic...... isolates produced aflatoxins in the culture medium in varying quantities. Plates of aflatoxigenic A. flavus L strains fluoresced bluish purple/lavender around the colony on the obverse and pastel blue on the reverse side due to aflatoxin B production while those of A. minisclerotigenes, A. parasiticus...

  11. Diagnostic Value of Processing Cytologic Aspirates of Renal Tumors in Agar Cell (Tissue) Blocks

    DEFF Research Database (Denmark)

    Smedts, F.; Schrik, M.; Horn, T.

    2010-01-01

    smears were prepared after each aspiration for conventional cytology and the remaining aspirate was processed for the improved agar microbiopsy (AM) method. Conventional cytology slides, AM slides and surgical specimens were diagnosed separately, after which the diagnoses were compared....... Immunohistochemistry was performed as required on the AM sections. Surgical specimens served as the gold standard. Results In 53% of conventional cytologic smears, the cellular yield was sufficient to render a correct diagnosis. In 12% the diagnosis was incorrect, in 21% only a differential diagnosis could be fin......-initiated, and in 14% too few diagnostic cells were present in the conventional smears for cytologic diagnosis. It was, however, possible to correctly diagnose histologic sections from 97% of AM tissue blocks. In 11 cases this was facilitated with immunochemistry. In only 1 case did the AM tissue block contain too few...

  12. Photoluminescent polymer electrolyte based on agar and containing europium picrate for electrochemical devices

    International Nuclear Information System (INIS)

    Lima, E.; Raphael, E.; Sentanin, F.; Rodrigues, L.C.; Ferreira, R.A.S.; Carlos, L.D.; Silva, M.M.; Pawlicka, A.

    2012-01-01

    Highlights: ► We prepared ionic conducting membranes for the specific requirements of the device. ► Luminescent reporter groups, with many applications in biotechnology. ► Thermal and electrochemical stability of electrolytes is adequate for application. - Abstract: Dispersion of photoluminescent rare earth metal complexes in polymer matrices is of great interest due to the possibility of avoiding the saturation of the photoluminescent signal. The possibility of using a natural ionic conducting polymer matrix was investigated in this study. Samples of agar-based electrolytes containing europium picrate were prepared and characterized by physical and chemical analyses. The FTIR spectra indicated strong interaction of agar O-H and 3,6-anhydro-galactose C-O groups with glycerol and europium picrate. The DSC analyses revealed no glass transition temperature of the samples in the −60 to 250 °C range. From the thermogravimetry (TG), a thermal stability of the samples of up to 180 °C was stated. The membranes were subjected to ionic conductivity measurement, which provided the values of 2.6 × 10 −6 S/cm for the samples with acetic acid and 1.6 × 10 −5 S/cm for the samples without acetic acid. Moreover, the temperature-dependent ionic conductivity measurements revealed both Arrhenius and VTF models of the conductivity depending on the sample. Surface visualization through scanning electron microscopy (SEM) demonstrated good uniformity. The samples were also applied in small electrochromic devices and showed good electrochemical stability. The present work confirmed that these materials may perform as satisfactory multifunctional component layers in the field of electrochemical devices.

  13. Evaluation of agar dilution and broth microdilution methods to determine the disinfectant susceptibility.

    Science.gov (United States)

    Wu, Guoyan; Yang, Qianru; Long, Mei; Guo, Lijuan; Li, Bei; Meng, Yue; Zhang, Anyun; Wang, Hongning; Liu, Shuliang; Zou, Likou

    2015-11-01

    A variety of disinfectants have been widely used in veterinary hygiene, food industries and environments, which could induce the development of bacterial resistance to disinfectants. The methods used to investigate antimicrobial effects of disinfectant vary considerably among studies, making comparisons difficult. In this study, agar dilution and broth microdilution methods were used to compare the antimicrobial activities of four quaternary ammonium compounds (QACs) against foodborne and zoonotic pathogens. The potential relationship between the presence of QACs resistance genes and phenotypic resistance to QACs was also investigated. Our results indicated that the minimum inhibitory concentrations (MICs) determined by two methods might be different depended upon different QACs and bacteria applied. Regardless of the testing methods, Klebsiella pneumoniae was more tolerant among Gram-negative strains to four QACs, followed by Salmonella and Escherichia coli. The agreement between MICs obtained by the two methods was good, for benzalkonium chloride (78.15%), didecyldimethylammonium chloride (DDAC) (82.35%), cetylpyridinium chloride (CTPC) (97.48%) and cetyltrimethylammonium bromide (CTAB) (99.16%), respectively. Among all Gram-negative bacteria, 94.55% (n=52) of qacEΔ1-positive strains showed higher MICs (512 mg l(-1)) to CTAB. The qacEΔ1 gene was highly associated (P<0.05) with the high MICs of QACs (⩾512 mg l(-1)). In addition, DDAC remained as the most effective disinfectant against both Gram-positive and Gram-negative bacteria. This is the first study that compared the agar dilution and broth microdilution methods to assess the antimicrobial activity of QACs. The study demonstrated the need to standardize method that would be used in evaluating QACs antimicrobial properties in the future.

  14. Spherical agarose-coated magnetic nanoparticles functionalized with a new salen for magnetic solid-phase extraction of uranyl ion

    International Nuclear Information System (INIS)

    Serenjeh, Fariba Nazari; Hashemi, Payman; Ghiasvand, Ali Reza; Naeimi, Hossein; Zakerzadeh, Elham

    2016-01-01

    The authors describe a method for magnetic solid phase extraction of uranyl ions from water samples. It is based on the use of spherical agarose-coated magnetic nanoparticles along with magnetic field agitation. The salen type Schiff base N,N’-bis(4-hydroxysalicylidene)-1,2-phenylenediamine was synthesized from resorcinol in two steps and characterized by infrared and nucleic magnetic resonance spectroscopies. The particles were then activated by an epichlorohydrin method and functionalized with the Schiff base which acts as a selective ligand for the extraction of UO 2 (II). Following preconcentration and elution with HCl, the ions were quantified by spectrophotometry using Arsenazo III as the indicator. The effects of pH value, ionic strength and amount of the adsorbent on the extraction of UO 2 (II) were optimized by a multivariate central composite design method. Six replicate analyses under optimized conditions resulted in a recovery of 96.6 % with a relative standard deviation of 3.4 % for UO 2 (II). The detection limit of the method (at a signal-to-noise ratio of 3σ) is 10 μg L -1 . The method was successfully applied to the determination of UO 2 (II) in spiked water samples. (author)

  15. Heparins, low-molecular-weight heparins, and other glycosaminoglycans analyzed by agarose gel electrophoresis and azure A-silver staining.

    Science.gov (United States)

    Wang, L; Malsch, R; Harenberg, J

    1997-01-01

    A sensitive, nonradioactive azure A-silver staining method combining agarose gel electrophoresis was established and evaluated. Unfractionated heparins (UFHs), low-molecular-weight heparins (LMWHs), heparan sulfate (HS), chondroitin sulfate A (CSA), dermatan sulfate (DS), keratan sulfate (KS), and hyaluronic acid (HA) were analyzed. The detection limit of the method was 0.5 ng for heparin, LMWH, HA, CSA, and DS, 2 ng for KS, and 6 ng for HA in the 2-microliter sample volume. Dilution curves demonstrated linear correlation between the logarithm of the concentration of glycosaminoglycans (GAGs) and their optical absorbance at 548 nm. The linear ranges were 1 to 500 ng/microliter for heparins, LMWHs, HS, DS, and CSA, 3 to 500 ng/microliter for KS, and 8 to 500 ng/microliter for HA. GAGs have their characteristic migration patterns and their Rf value decreased from CSA to KS, DS, HS, heparin, and HA. The differences were described for heparins and LMWHs. LMWHs migrated faster and displayed broader bands than unfractionated heparins. It was also observed that some unfractionated heparins contained low sulfated GAGs as contamination, which seemed to be DS as judged by their migration patterns.

  16. BDNF gene delivery within and beyond templated agarose multi-channel guidance scaffolds enhances peripheral nerve regeneration

    Science.gov (United States)

    Gao, Mingyong; Lu, Paul; Lynam, Dan; Bednark, Bridget; Campana, W. Marie; Sakamoto, Jeff; Tuszynski, Mark

    2016-12-01

    Objective. We combined implantation of multi-channel templated agarose scaffolds with growth factor gene delivery to examine whether this combinatorial treatment can enhance peripheral axonal regeneration through long sciatic nerve gaps. Approach. 15 mm long scaffolds were templated into highly organized, strictly linear channels, mimicking the linear organization of natural nerves into fascicles of related function. Scaffolds were filled with syngeneic bone marrow stromal cells (MSCs) secreting the growth factor brain derived neurotrophic factor (BDNF), and lentiviral vectors expressing BDNF were injected into the sciatic nerve segment distal to the scaffold implantation site. Main results. Twelve weeks after injury, scaffolds supported highly linear regeneration of host axons across the 15 mm lesion gap. The incorporation of BDNF-secreting cells into scaffolds significantly increased axonal regeneration, and additional injection of viral vectors expressing BDNF into the distal segment of the transected nerve significantly enhanced axonal regeneration beyond the lesion. Significance. Combinatorial treatment with multichannel bioengineered scaffolds and distal growth factor delivery significantly improves peripheral nerve repair, rivaling the gold standard of autografts.

  17. Modulating the oxidative environment during mesenchymal stem cells chondrogenesis with serum increases collagen accumulation in agarose culture.

    Science.gov (United States)

    Tangtrongsup, Suwimol; Kisiday, John D

    2018-01-01

    Chondrogenesis of mesenchymal stem cells (MSCs) is induced in culture conditions that have been associated with oxidative stress, although the extent to which the oxidative environment affects differentiation and extracellular matrix (ECM) accumulation is not known. The objectives of this study were to evaluate the oxidative environment during MSCs chondrogenesis in conventional serum-free medium, and the effect of serum-supplementation on intracellular reactive oxygen species (ROS) and chondrogenesis. Young adult equine MSCs were seeded into agarose and cultured in chondrogenic medium, with or without 5% fetal bovine serum (FBS), for up to 15 days. Samples were evaluated for intracellular ROS, the antioxidant glutathione, ECM and gene expression measures of chondrogenesis, and carbonylation as an indicator of oxidative damage. Intracellular ROS increased with time in culture, and was lower in medium supplemented with FBS. Glutathione decreased ∼12-fold during early chondrogenesis (p environment during MSC chondrogenesis, and suggested that lowering ROS may be an effective approach to increase collagen accumulation. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:506-514, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  18. First-in-Human Phase 1 Trial of Agarose Beads Containing Murine RENCA Cells in Advanced Solid Tumors

    Directory of Open Access Journals (Sweden)

    Barry H. Smith

    2016-01-01

    Full Text Available Purpose Agarose macrobeads containing mouse renal adenocarcinoma cells (RMBs release factors, suppressing the growth of cancer cells and prolonging survival in spontaneous or induced tumor animals, mediated, in part, by increased levels of myocyte-enhancing factor (MEF2D via EGFR-and AKT-signaling pathways. The primary objective of this study was to determine the safety of RMBs in advanced, treatment-resistant metastatic cancers, and then its efficacy (survival, which is the secondary objective. Methods Thirty-one patients underwent up to four intraperitoneal implantations of RMBs (8 or 16 macrobeads/kg via laparoscopy in this single-arm trial (FDA BB-IND 10091; NCT 00283075. Serial physical examinations, laboratory testing, and PET-CT imaging were performed before and three months after each implant. Results RMBs were well tolerated at both dose levels (mean 660.9 per implant. AEs were (Grade 1/2 with no treatment-related SAEs. Conclusion The data support the safety of RMB therapy in advanced-malignancy patients, and the preliminary evidence for their potential efficacy is encouraging. A Phase 2 efficacy trial is ongoing.

  19. Electrophoretic study of whey proteins in Holstein cows with clinical and subclinical mastitis by Agarose gel procedure

    Directory of Open Access Journals (Sweden)

    A Davasaz Tabrizi

    2009-02-01

    Full Text Available Mastitis is one the most important economic diseases in dairy cattle industry, which causes reduction in milk production, treatment expenses, reduction in herd genetic progress and fall in quality of milk. The aim of this study was to examine the milk proteins of Holstein dairy cows with different grades of clinical and subclinical mastitis. During the sampling period, none of the cows were in late pregnancy or at early lactation and also had no parasitemia and any other inflammatory diseases.  Clinical and laboratory examinations which were carried out completely revealed the cows were all healthy. They were fed on corn silage, concentrate and alfalfa. In this study, the cows were divided into five groups, each group with 25 cases. For this purpose, milk samples were collected from 125 dairy cattle of two large dairy farms in Tabriz. All the cows were in the lactation period and they were milked three times a day. The groups consist of the control group with negative California mastitis test and negative culture, 2+ subclinical groups, 3+ subclinical group, sub acute clinical group and acute clinical group. The results of the whey electrophoresis using Agarose gel procedure indicated significant difference in albumin levels in all groups except the 2+ subclinical group compared with the control group (p

  20. Characterization of β -Glucosidase Produced by Aspergillus niger under Solid-State Fermentation and Partially Purified Using MANAE-Agarose.

    Science.gov (United States)

    Baraldo Junior, Anderson; Borges, Diogo G; Tardioli, Paulo W; Farinas, Cristiane S

    2014-01-01

    β -Glucosidase (BGL) is a hydrolytic enzyme with specificity for a wide variety of glycoside substrates, being an enzyme with a large range of biotechnological applications. However, enzyme properties can be different depending both on the microorganism and the cultivation procedure employed. Therefore, in order to explore potential biocatalytical applications of novel enzymes, their characterization is essential. In this work, a BGL synthesized by a selected strain of Aspergillus niger cultivated under solid-state fermentation (SSF) was partially purified and fully characterized in terms of optimum pH, temperature, and thermostability. The single-step purification using MANAE-agarose in a chromatographic column yielded an enzyme solution with specific activity (17.1 IU/mg protein) adequate for the characterization procedures. Electrophoresis SDS-PAGE and size-exclusion chromatography analysis resulted in an estimated molecular mass of 60 kDa. Higher enzyme activities were found in the range between 40 and 65°C and between pH 4 and 5.5, indicating an interesting characteristic for application in the hydrolysis of lignocellulosic biomass for biofuels production. Thermostability studies of purified BGL resulted in half-lives at 37°C of 56.3 h and at 50°C of 5.4 h. These results provide support for further studies of this enzyme towards revealing its potential biotechnological applications.

  1. Agarose gel electrophoresis of cerebrospinal fluid proteins of dogs after sample concentration using a membrane microconcentrator technique.

    Science.gov (United States)

    Gama, Fernanda Gomes Velasque; Santana, Aureo Evangelista; Filho, Eugênio de Campos; Nogueira, Cláudia Aparecida da Silva

    2007-03-01

    Cerebrospinal fluid (CSF) is produced in the cerebral ventricles through ultrafiltration of plasma and active transport mechanisms. Evaluation of proteins in CSF may provide important information about the production of immunoglobulins within the central nervous system as well as possible disturbances in the blood-brain barrier. The objective of this study was to measure the concentration and fractions of protein in CSF samples using a membrane microconcentrator technique followed by electrophoresis, and to compare the protein fractions obtained with those in serum. CSF samples from 3 healthy dogs and 3 dogs with canine distemper virus infection were concentrated using a membrane microconcentrator having a 0.5 to 30,000 d nominal molecular weight limit (Ultrafree, Millipore, Billerica, MA, USA). Protein concentration was determined before and after concentration. Agarose gel electrophoresis was done on concentrated CSF samples, serum, and serial dilutions of one of the CSF samples. Electrophoretic bands were clearly identified in densitometer tracings in CSF samples with protein concentrations as low as 1.3 g/dL. The higher CSF protein concentration in dogs with distemper was mainly the result of increased albumin concentration. The microconcentrating method used in this study enables characterization of the main protein fractions in CSF by routine electrophoresis and may be useful for interpreting the underlying cause of changes in CSF protein concentrations.

  2. Zinc-air cell with KOH-treated agar layer between electrode and electrolyte containing hydroponics gel

    Energy Technology Data Exchange (ETDEWEB)

    Otham, R. [International Islamic University, Kuala Lumpur (Malaysia); Yahaya, A. H. [University of Malaya, Dept. of Chemistry, Kuala Lumpur (Malaysia); Arof, A. K. [University of Malaya, Dept. of Physics, Kuala Lumpur (Malaysia)

    2002-07-01

    Zinc-air electrochemical power sources possess the highest density compared to other zinc anode batteries, due their free and unlimited supply from the ambient air. In this experiment zinc-air cells have been fabricated employing hydroponics gel as an alternative alkaline electrolyte gelling agent. Thin KOH-treated agar layer was applied between the electrode-electrolyte interfaces which produced significant enhancement of the cells' capacities, indicating that the application of thin agar layer will improve the electrode-gelled electrolyte interfaces. Promising results have been achieved with porous zinc anode prepared from dried zinc-graphite-gelatinized agar paste; e g. a zinc-air cell employing a porous zinc anode has demonstrated a capacity of 1470 mAh rated at 0.1 A continuous discharge. 32 refs., 9 figs.

  3. Use of meropenem Adatabs dissolved in MacConkey agar for screening NDM-1 positive Enterobacteriaceae in faecal surveillance cultures.

    Science.gov (United States)

    Choudhury, Saugata; Chan, Kian Sing; Koh, Tse Hsien

    2012-08-01

    Carbapenem resistance due to metallo-β-lactamases (MBLs) in Enterobacteriaceae has gained much prominence in recent months. The emergence and subsequent spread of New Delhi metallo-β-lactamase-1 (NDM-1) constitutes a potential threat in terms of the management of affected patients and institutional infection control efforts. We evaluated an in-house prepared meropenem impregnated MacConkey agar versus CHROMagar KPC. The lowest limit of detection (LLD) was compared for nine clinical isolates of NDM-1 producing Enterobacteriaceae on the above mentioned agar media. LLD was comparable for all the nine clinical isolates on both media. The cost of the antibiotic impregnated MacConkey agar was considerably lower (US$0.39) as compared to the commercial media, while its performance remained unaltered for a period of at least 8 weeks of storage. The in-house medium proved to be a suitable and cheap alternative to the CHROMagar KPC.

  4. SYBR Green I staining of pulsed field agarose gels is a sensitive and inexpensive way of quantitating DNA double-strand breaks in mammalian cells.

    OpenAIRE

    Kiltie, A E; Ryan, A J

    1997-01-01

    Pulsed field gel electrophoresis (PFGE) is widely used to measure DNA double strand breaks (dsb). The DNA of cultured cells can be prelabelled with radioactivity, which helps greatly in detection and quantitation of DNA dsb. However, this approach cannot be used with non-cycling cells from biopsy material. We describe a method which uses SYBR Green I to stain DNA in dried agarose gels. DNA is detected and analysed using readily available camera equipment and image analysis software. This meth...

  5. Enhanced chlorine resistance of tap water-adapted Legionella pneumophila as compared with agar medium-passaged strains.

    Science.gov (United States)

    Kuchta, J M; States, S J; McGlaughlin, J E; Overmeyer, J H; Wadowsky, R M; McNamara, A M; Wolford, R S; Yee, R B

    1985-07-01

    Previous studies have shown that bacteria maintained in a low-nutrient "natural" environment such as swimming pool water are much more resistant to disinfection by various chemical agents than strains maintained on rich media. In the present study a comparison was made of the chlorine (Cl2) susceptibility of hot-water tank isolates of Legionella pneumophila maintained in tap water and strains passaged on either nonselective buffered charcoal-yeast extract or selective differential glycine-vancomycin-polymyxin agar medium. Our earlier work has shown that environmental and clinical isolates of L. pneumophila maintained on agar medium are much more resistant to Cl2 than coliforms are. Under the present experimental conditions (21 degrees C, pH 7.6 to 8.0, and 0.25 mg of free residual Cl2 per liter, we found the tap water-maintained L. pneumophila strains to be even more resistant than the agar-passaged isolates. Under these conditions, 99% kill of tap water-maintained strains of L. pneumophila was usually achieved within 60 to 90 min compared with 10 min for agar-passaged strains. Samples from plumbing fixtures in a hospital yielded legionellae which were "super"-chlorine resistant when assayed under natural conditions. After one agar passage their resistance dropped to levels of comparable strains which had not been previously exposed to additional chlorination. These studies more closely approximate natural conditions than our previous work and show that tap water-maintained L. pneumophila is even more resistant to Cl2 than its already resistant agar medium-passaged counterpart.

  6. Variation in the excitability of developed D. discoideum cells as a function of agar concentration in the substrate

    Science.gov (United States)

    Oikawa, Noriko; Bae, Albert; Amselem, Gabriel; Bodenschatz, Eberhard

    2010-03-01

    In the absence of nutrients, Dictyostelium discoideum cells enter a developmental cycle--they signal each other, aggregate, and ultimately form fruiting bodies. During the signaling stage, the cells relay waves of cyclic adenosine 3',5' monophosphate (cAMP). We observed a transition from spiral to circular patterns in the signaling wave, depending on the agar concentration of the substrate. In this talk we will present the changes in the times for the onset of signaling and synchronization versus agar concentration, as measured by spectral entropy. We also will discuss the origin of these effects.

  7. Cat and Dog Primordial Follicles Enclosed in Ovarian Cortex Sustain Viability after In vitro Culture on Agarose Gel in a Protein-Free Medium

    Science.gov (United States)

    Fujihara, M; Comizzoli, P; Wildt, DE; Songsasen, N

    2014-01-01

    Contents Our objective was to examine the influences of differing media, protein supplementation and the microenvironment on cat vs dog primordial follicle viability in vitro. Ovarian cortical slices were cultured for 3, 9 or 15 days in α-minimum essential medium (α-MEM) or MEM supplemented with 10% fetal bovine serum (FBS), 10% knock-out serum replacement (KSR) or 0.1% polyvinyl alcohol (protein free). In a separate study, cat and dog ovarian tissues were cultured in protein-free α-MEM and MEM, respectively, in cell culture inserts, on 1.5% agarose gel or in 24-well cell culture plates (control). Follicle viability was assessed in both studies using calcein AM/ethidium homodimer and histological evaluation with haematoxylin/eosin staining. No cat follicle sustained viability beyond 9 days of in vitro culture in α-MEM compared to 37.5% of those incubated for 15 days in MEM in protein-free condition (p dog follicle viability (32.7% vs 8.1%) in protein-free condition at 15 days. Serum was detrimental (p cat follicle viability, whereas the latter was superior (p dog follicle survival. Likewise, dog follicle viability was enhanced (p cat, the agarose gel better (p cat vs the dog. A key factor to enhancing survival of these early stage follicles in culture appears to be the use of agarose gel, which enhances follicle viability, perhaps by promoting gas exchange. PMID:23279476

  8. Improvement of Karmali agar by addition of polymyxin B for the detection of Campylobacter jejuni and C. coli in whole-chicken carcass rinse.

    Science.gov (United States)

    Chon, Jung-Whan; Kim, Hyunsook; Yim, Jin-Hyeok; Song, Kwang-Young; Moon, Jin-San; Kim, Young-Jo; Seo, Kun-Ho

    2013-05-01

    The Karmali agar was modified by supplementation with a high concentration of polymyxin B. The goal of the study was to evaluate the effect of a high concentration of polymyxin B on the ability and selectivity of the modified Karmali agar to isolate Campylobacter jejuni and Campylobacter coli from whole chicken carcass rinse. A total of 80 whole chickens were rinsed with 400 mL of buffer peptone water. The rinsed samples were incubated with 2× blood-free modified Bolton enrichment broth for 48 h, and then streaked onto unmodified Karmali agar and modified Karmali agar supplemented with 100000 IU/L polymixin B (P-Karmali agar). The suspected colonies were finally confirmed by colony PCR. The P-Karmali agar exhibited a significantly better (P Food Technologists®

  9. Optimization of the agar-gel method for isolation of migrating Ascaris suum larvae from the liver and lungs of pigs

    DEFF Research Database (Denmark)

    Saeed, I.; Roepstorff, A.; Rasmussen, T.

    2001-01-01

    Experiments on use of an agar-gel method for recovery of migrating Ascaris suum larvae from the liver and lungs of pigs were conducted to obtain fast standardized methods. Subsamples of blended tissues of pig liver and lungs were mixed with agar to a final concentration of 1% agar and the larvae...... allowed to migrate out of the agar-gel into 0.9% NaCl at 38 degreesC. The results showed that within 3 h more than 88% of the recoverable larvae migrated out of the liver agar-gel and more than 83% of the obtained larvae migrated out of the lung agar-gel. The larvae were subsequently available in a very...

  10. Comparison of sorbitol MacConkey agar and a two-step method which utilizes enzyme-linked immunosorbent assay toxin testing and a chromogenic agar to detect and isolate enterohemorrhagic Escherichia coli.

    Science.gov (United States)

    Novicki, T J; Daly, J A; Mottice, S L; Carroll, K C

    2000-02-01

    Enterohemorrhagic Escherichia coli (EHEC) and specifically serotype O157:H7 are a significant cause of hemorrhagic gastrointestinal disease and the hemolytic uremic syndrome. Methods currently used in clinical microbiology labs, such as sorbitol-MacConkey (SMAC) agar, reliably detect only O157:H7. We have evaluated a two-step method that has the potential to identify and isolate all EHEC serotypes, including serotype O157:H7. This method utilizes a chromogenic selective-differential medium for the isolation of E. coli together with an enzyme-linked immunosorbent assay (ELISA) that detects the Shiga-like toxins Stx1 and Stx2. Both are commercially available and usable in a wide range of clinical microbiology laboratories. Compared to a Vero cell cytotoxic assay, SMAC had sensitivities of 23.5% for the identification of all EHEC serotypes and of 50.0% for the identification of O157:H7 alone. The two-step method had sensitivities of 76.5 and 100%, respectively. The ELISA alone had a sensitivity of 82.4% in the detection of Stx1 and Stx2. The specificity was 100% in all cases. Overall, 14 EHEC isolates were obtained: 8 (58%) O157:H7, 2 (14%) O26, 2 (14%) O111:NM, 1 (7%) O103:H2, and 1 (7%) O121:H19. All but one were isolated during the months of May to September. The two-step method was found to be considerably more expensive than SMAC for both positive and negative samples.

  11. Radiofrequency ablation: importance of background tissue electrical conductivity--an agar phantom and computer modeling study.

    Science.gov (United States)

    Solazzo, Stephanie A; Liu, Zhengjun; Lobo, S Melvyn; Ahmed, Muneeb; Hines-Peralta, Andrew U; Lenkinski, Robert E; Goldberg, S Nahum

    2005-08-01

    To determine whether radiofrequency (RF)-induced heating can be correlated with background electrical conductivity in a controlled experimental phantom environment mimicking different background tissue electrical conductivities and to determine the potential electrical and physical basis for such a correlation by using computer modeling. The effect of background tissue electrical conductivity on RF-induced heating was studied in a controlled system of 80 two-compartment agar phantoms (with inner wells of 0.3%, 1.0%, or 36.0% NaCl) with background conductivity that varied from 0.6% to 5.0% NaCl. Mathematical modeling of the relationship between electrical conductivity and temperatures 2 cm from the electrode (T2cm) was performed. Next, computer simulation of RF heating by using two-dimensional finite-element analysis (ETherm) was performed with parameters selected to approximate the agar phantoms. Resultant heating, in terms of both the T2cm and the distance of defined thermal isotherms from the electrode surface, was calculated and compared with the phantom data. Additionally, electrical and thermal profiles were determined by using the computer modeling data and correlated by using linear regression analysis. For each inner compartment NaCl concentration, a negative exponential relationship was established between increased background NaCl concentration and the T2cm (R2= 0.64-0.78). Similar negative exponential relationships (r2 > 0.97%) were observed for the computer modeling. Correlation values (R2) between the computer and experimental data were 0.9, 0.9, and 0.55 for the 0.3%, 1.0%, and 36.0% inner NaCl concentrations, respectively. Plotting of the electrical field generated around the RF electrode identified the potential for a dramatic local change in electrical field distribution (ie, a second electrical peak ["E-peak"]) occurring at the interface between the two compartments of varied electrical background conductivity. Linear correlations between the E

  12. Low melting point agarose beads as a standard method for plantlet regeneration from protoplasts within the Cichorium genus.

    Science.gov (United States)

    Deryckere, Dieter; Eeckhaut, Tom; Van Huylenbroeck, Johan; Van Bockstaele, Erik

    2012-12-01

    A standard method has been developed with which we are able to fully regenerate protoplasts of different Cichorium species. For the first time, endive protoplasts have been regenerated into plantlets. Protoplast regeneration is essential for somatic hybridizations. In this study, a standard method for plantlet regeneration from Cichorium protoplasts was developed. We evaluated the effect of the low melting point agarose (LMPA) bead technique on the regeneration capacity of protoplasts of seven C. intybus and four C. endivia genotypes. The LMPA bead technique was more efficient than culture in liquid or solid medium and allowed us to obtain plating efficiencies up to 4.9 % in C. intybus genotypes and efficiencies of up to 0.7 % in C. endivia genotypes. Moreover, the LMPA bead technique offers great advantages over liquid and solid culture systems: the media can be readily refreshed, protoplasts can be monitored separately, and microcalli can easily be removed from the beads. This increased efficiency was observed for all of the 11 Cichorium genotypes tested. Shoot formation was induced more efficiently when using 0.5 mg l(-1) indole-3-acetic acid-enriched medium (up to 87.5 % of the protoplast-derived calli started shoot development) compared to 1-naphthaleneacetic acid-enriched medium. The LMPA bead technique optimized in this study enabled for the first time the full plantlet regeneration from protoplasts of C. endivia genotypes and increased the protoplast regenerating ability in other Cichorium species. This fine-tuned LMPA bead technique can therefore be applied for protoplast regeneration after protoplast fusions of the genus Cichorium.

  13. Choline chloride based ionic liquid analogues as tool for the fabrication of agar films with improved mechanical properties

    Science.gov (United States)

    In the present paper, we test the suitability of Choline-Cl/urea (DES-U) and Choline-Cl/glycerol (DES-G) eutectic mixtures at 1:2 molar ratios for the production of agar biodegradable films. A three-step process is proposed: pre-solubilization of polymer in DES followed by compression-molding and s...

  14. Properties and characterization of agar/CuNP bionanocomposite films prepared with different copper salts and reducing agents.

    Science.gov (United States)

    Shankar, Shiv; Teng, Xinnan; Rhim, Jong-Whan

    2014-12-19

    Various types of agar-based bio-nanocomposite (BNC) films were prepared by blending agar and six different copper nanoparticles (CuNPs) with different shapes and sizes obtained from three different sources of copper salts and two different reducing agents. The BNC films were characterized by UV-visible, FE-SEM, FT-IR, and XRD. The thermogravimetric study showed that the melting point of BNC films was increased when ascorbic acid was used as a reducing agent for CuNPs synthesis. Apparent surface color and transmittance of agar film was greatly influenced by the reinforcement of CuNPs. However, mechanical and water vapor barrier properties did not change significantly (p>0.05) by blending with CuNPs. Tensile modulus and tensile strength decreased slightly for all types of CuNPs reinforced while elongation at break slightly increased when CuNPs produced by ascorbic acid were blended. The agar bio-nanocomposite films showed profound antibacterial activity against both Gram-positive and Gram-negative food-borne pathogenic bacteria. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Effects of immersion disinfection of agar-alginate combined impressions on the surface properties of stone casts.

    Science.gov (United States)

    Iwasaki, Yukiko; Hiraguchi, Hisako; Iwasaki, Eriko; Yoneyama, Takayuki

    2016-01-01

    This study investigated the effects of disinfection of agar-alginate combined impressions on the surface properties of the resulting stone casts. Two brands of cartridge-form agar impression material and one alginate impression material were used. Agar-alginate combined impressions of smooth glass plates were prepared. The impressions were immersed in 0.55% ortho-phthalaldehyde solution or 0.5% sodium hypochlorite solution for 1, 3, 5 and 10 min. A stone cast made with an impression that had not been immersed was prepared as a control. The surface roughness (Ra) of the stone casts was measured, and the cast surfaces were observed by SEM. Immersion of agar-alginate combined impressions in 0.5% sodium hypochlorite solution for up to 10 min had no serious adverse effects on the surface properties of the stone casts. In contrast, even 1 min of immersion in 0.55% ortho-phthalaldehyde solution caused deterioration of the cast surface properties.

  16. Arthrornyces and Blastosporella, two new genera of conidia-producing lyophylloid agarics (Agaricales, Basidiornycota) from the neotropics

    Science.gov (United States)

    Timothy J. Baroni; Ana Esperanza Franco-molano; D. Jean Lodge; Daniel L. Lindner; Egon Horak; Valerie Hofstetter

    2007-01-01

    Two new genera encompassing three new species of lyophylloid agarics that produce conidia on the basidiomata are described. Arthromyces is a genus comprised of two very different arthrospore-producing mushroom species found in the Greater Antilles and Central America. Blastosporella is a monotypic genus with spherical balls of...

  17. Prospective Two-Center Comparison of Three Chromogenic Agars for Methicillin-Resistant Staphylococcus aureus Screening in Hospitalized Patients

    NARCIS (Netherlands)

    Dodémont, Magali; Verhulst, Carlo; Nonhoff, Claire; Nagant, Carole; Denis, Olivier; Kluytmans, Jan

    Three chromogenic media, chromID MRSA SMART (SMART), chromID MRSA first generation (chromID), and Brilliance MRSA (OX2), were evaluated for methicillin-resistant Staphylococcus aureus (MRSA) screening using 1,220 samples. The sensitivity at 24 h was significantly better with the SMART agar (66.4%)

  18. Agar/gelatin bilayer gel matrix fabricated by simple thermo-responsive sol-gel transition method.

    Science.gov (United States)

    Wang, Yifeng; Dong, Meng; Guo, Mengmeng; Wang, Xia; Zhou, Jing; Lei, Jian; Guo, Chuanhang; Qin, Chaoran

    2017-08-01

    We present a simple and environmentally-friendly method to generate an agar/gelatin bilayer gel matrix for further biomedical applications. In this method, the thermally responsive sol-gel transitions of agar and gelatin combined with the different transition temperatures are exquisitely employed to fabricate the agar/gelatin bilayer gel matrix and achieve separate loading for various materials (e.g., drugs, fluorescent materials, and nanoparticles). Importantly, the resulting bilayer gel matrix provides two different biopolymer environments (a polysaccharide environment vs a protein environment) with a well-defined border, which allows the loaded materials in different layers to retain their original properties (e.g., magnetism and fluorescence) and reduce mutual interference. In addition, the loaded materials in the bilayer gel matrix exhibit an interesting release behavior under the control of thermal stimuli. Consequently, the resulting agar/gelatin bilayer gel matrix is a promising candidate for biomedical applications in drug delivery, controlled release, fluorescence labeling, and bio-imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Detection of Fusobacterium nucleatum in two cases of empyema and lung abscess using paromomycin-vancomycin supplemented Brucella HK agar.

    Science.gov (United States)

    Nagaoka, Kentaro; Yanagihara, Katsunori; Morinaga, Yoshitomo; Kohno, Shigeru

    2017-02-01

    Fusobacterium nucleatum was found in patients with empyema or pulmonary abscess, using paromomycin-vancomycin Brucella HK agar. In vitro examination revealed that growth of the strains differed significantly in different media. Clinicians should be aware that suboptimal F. nucleatum cultivation methods may result in an underestimation of its frequency. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Intelligent pH indicator film composed of agar/potato starch and anthocyanin extracts from purple sweet potato.

    Science.gov (United States)

    Choi, Inyoung; Lee, Jun Young; Lacroix, Monique; Han, Jaejoon

    2017-03-01

    A new colorimetric pH indicator film was developed using agar, potato starch, and natural dyes extracted from purple sweet potato, Ipomoea batatas. Both agar and potato starch are solid matrices used to immobilize natural dyes, anthocyanins. The ultraviolet-visible (UV-vis) spectrum of anthocyanin extract solutions and agar/potato starch films with anthocyanins showed color variations to different pH values (pH 2.0-10.0). Fourier transform infrared (FT-IR) and UV-vis region spectra showed compatibility between agar, starch, and anthocyanin extracts. Color variations of pH indicator films were measured by a colorimeter after immersion in different pH buffers. An application test was conducted for potential use as a meat spoilage sensor. The pH indicator films showed pH changes and spoilage point of pork samples, changing from red to green. Therefore, the developed pH indicator films could be used as a diagnostic tool for the detection of food spoilage. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Comparative study of agar gel immunodiffusion (AGID protocols for the diagnosis of equine infectious anemia in Brazil

    Directory of Open Access Journals (Sweden)

    Fernanda Gonçalves Oliveira

    2014-02-01

    Full Text Available To evaluate the Equine Infectious Anemia (EIA agar gel immunodiffusion (AGID protocols, two different kits commercially available in Brazil were used: an imported kit (kit A and a domestically produced kit (kit B. Kit A was submitted to the protocols recommended by the World Organization for Animal Health (OIE and the protocol recommended by the Ministério da Agricultura Pecuária e Abastecimento (MAPA. Kit B, the Brazilian kit, was submitted only to the MAPA-recommended protocol and was used as a reference in this study. A total of 345 equid serum samples, including field samples, serum sets from official laboratories and a weak positive serum control from National Veterinary Services Laboratories (NVSL, were used. Parameters such as the sensitivity of kit A in the two protocols, the detection limit of kits and the occurrence of nonspecific reactions or non-identity were evaluated. When Kit A was used for an AGID procedure performed according to the OIE-recommended protocol, the kit demonstrated good agreement with kit B and 99 % relative sensitivity. However, when kit A was processed according to the MAPA-recommended protocol, it failed to detect 1.16 % of weak positive samples and its relative sensitivity decreased to 96 %. The detection limit of kit A was lower than the detection limit of kit B for weak positive samples in both protocols. The occurrence of nonidentity reactions was higher with kit B than with kit A. The training of veterinarians to ensure the correct execution of the AGID test protocol should be intensified in Brazil.

  2. Thin-layer agar (TL7H11 for rapid isolation of Mycobacterium tuberculosis in sputum specimens

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    Habiba Binte Alam

    2016-08-01

    Full Text Available Background: Tuberculosis (TB remains one of the major causes of death from a single infectious agent worldwide. The early detection of new cases of pulmonary tuberculosis is an important goal in tuberculosis control program.Objective: 1n this study, thin layer agar (TLA culture was compared with Lowenstein-Jensen (LJ culture for rapid detection of pulmonary tuberculosis. Methods: It was a cross sectional study conducted in National Tuberculosis Reference Labora­tory (NTRL of National Institute of Disease of Chest and Hospital (NIDCH, Dhaka, from July 2010 to June 2011. A total of 100 sputum smear positive for acid fast bacilli (AFB by Z-N staining, pulmonary tuberculosis patients were included in this study. Samples were processed by modified Petroff method and then cultured on thin layer 7H11(TL7H11 plates and L-J tubes. TL7H11 plates were observed microscopically for rnicrocolony growth once a week for 6 weeks, and L-J tubes were observed once a week for 8 weeks. Results: The recovery rates of mycobacteria on only TLA, only LJ and on both media were 90%, 97% and 88% respectively. Overall positivity was 99% in both L-J and TLA media. Mean time for detection of mycobacteria on TLA was 9.04±1.66 days compared to 21.78±6.19 days on L-J media. The rate of contamination was higher (6% in L-J media than in TLA media (4%. Conclusion: The TL7H11 media can be used as an alternative to the Lowenstein-Jensen medium for early isolation of mycobacteria in resource constrained settings.

  3. Tenacibaculum agarivorans sp. nov., an agar-degrading bacterium isolated from marine alga Porphyra yezoensis Ueda.

    Science.gov (United States)

    Xu, Zhen-Xing; Yu, Pei; Mu, Da-Shuai; Liu, Yan; Du, Zong-Jun

    2017-12-01

    A novel Gram-stain-negative, aerobic, rod-shaped, non-flagellated and agar-digesting marine bacterium, designated as HZ1 T , was isolated from the marine alga Porphyra yezoensis Ueda (AST58-103) collected from the coastal area of Weihai, PR China. Phylogenetic analysis based on 16S rRNA gene sequences placed HZ1 T in the genus Tenacibaculum, and it formed a distinct clade in the phylogenetic tree with the type strains of Tenacibaculum amylolyticum and Tenacibaculum skagerrakense, with 97.0 % and 96.7 % 16S rRNA gene sequence similarities, respectively. The DNA G+C content of the isolate was 31.8 mol%. HZ1 T contained MK-6 as the predominant menaquinone and iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C17 : 0 3-OH and iso-C15 : 1G as the major fatty acids. The major polar lipids were phosphatidylethanolamine, four unidentified lipids and five unidentified aminolipids. On the basis of the results of the phylogenetic analysis and phenotypic properties, it is concluded that HZ1 T represents a novel species of the genus Tenacibaculum, for which the name Tenacibaculumagarivorans sp. nov. is proposed. The type strain is HZ1 T (=MCCC 1H00174 T =KCTC 52476 T ).

  4. Physico-chemical and microstructural properties of fish gelatin/agar bio-based blend films.

    Science.gov (United States)

    Mohajer, Setareh; Rezaei, Masoud; Hosseini, Seyed Fakhreddin

    2017-02-10

    This study was conducted with the aim of improving the physico-chemical properties of fish gelatin (FG) based films. For this purpose, FG was blended with agar (AG) in different compositions to acquire biodegradable films (100:0, 80:20, 60:40, 50:50 & 0:100, FG:AG). The obtained results showed that the AG addition strongly increased the film rigidity and resistance to fracture, while reducing the film stretchability, mainly at 50FG: 50AG ratio. AG incorporation greatly reduced the water vapor permeability (WVP) and solubility of gelatin films, as this decline for the blend film with a 50:50 ratio of biopolymers has been about 41% and 66%, respectively (pfilms are the reduction of the UV-transmittance. Both polymers showed good compatibility, as demonstrated by scanning electron microscopy (SEM) and atomic force microscopy (AFM) images. Therefore, the blend composition influenced the properties of FG/AG bio-based films. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Selectivity of Mitis Salivarius agar and a new selective medium for oral streptococci in dogs.

    Science.gov (United States)

    Takada, Kazuko; Hayashi, Kazuhiko; Sasaki, Kayoko; Sato, Tsuneo; Hirasawa, Masatomo

    2006-09-01

    An evaluation on the applicability of Mitis Salivarius agar (MS) medium, commonly used for the detection of oral streptococci in human and animals, to dog specimens and the development of a new selective medium for isolating streptococci from the canine oral cavity are described. Oral samples from dogs were cultured on MS medium under anaerobic conditions. The predominant facultative anaerobic bacteria on MS plates were gram-negative rods. Selectivity of streptococci on MS medium was 21.2%. A new selective medium, designated MS-CAN-AE, was developed for the isolation of streptococci from the canine oral cavity. The average growth recovery of laboratory and clinically isolated strains of streptococci on MS-CAN-AE medium was 84.1% of that on MS medium. Gram-positive rods and gram-negative rods and cocci rarely grew on the MS-CAN-AE. The selectivity of MS-CAN-AE was 95.0% for clinical samples. MS-CAN-AE medium will be helpful for investigations of streptococci in the canine oral cavity.

  6. AKUNTABILITAS MORAL HAKIM DALAM MEMERIKSA, MENGADILI, DAN MEMUTUS PERKARA AGAR PUTUSANNYA BERKUALITAS

    Directory of Open Access Journals (Sweden)

    Sri Sutatiek

    2014-08-01

    Full Text Available Abstrak Independence of judges to examine, prosecute and deciding on cases must be balanced with the moral accountability that the court decisions are produced always have a certain quality. To create a quality decision, the decision containing justice for the majority of the community and can be executed, the need for moral accountability of each judge. MA can conduct training and supervision of judges internally. KY do externally supervision of judges. While judge themselves by believing that carry out the job as a judge is part of the devotion and worship.   Key words: accountability moral,  judge, qualified decisions   Abstrak Kemerdekaan hakim dalam memeriksa, mengadili dan memutus perkara harus diimbangi dengan akuntabilitas moral agar putusan pengadilan yang dihasilkan selalu berkualitas. Untuk menciptakan putusan yang berkualitas, yaitu putusan yang mengandung keadilan bagi sebagian besar masyarakat dan dapat dieksekusi, perlu adanya akuntabilitas moral setiap hakim. Pihak MA dapat melakukan pembinaan dan pengawasan hakim secara internal. Pihak KY melakukan pengawasan eksternal hakim. Sedangkan hakim sendiri salah satunya dengan meyakini bahwa melaksanakan pekerjaan sebagai hakim adalah bagian dari pengabdian dan ibadah. Kata kunci: akuntabilitas moral, hakim, putusan berkualitas.

  7. Functional properties of edible agar-based and starch-based films for food quality preservation.

    Science.gov (United States)

    Phan, The D; Debeaufort, F; Luu, D; Voilley, A

    2005-02-23

    Edible films made of agar (AG), cassava starch (CAS), normal rice starch (NRS), and waxy (glutinous) rice starch (WRS) were elaborated and tested for a potential use as edible packaging or coating. Their water vapor permeabilities (WVP) were comparable with those of most of the polysaccharide-based films and with some protein-based films. Depending on the environmental moisture pressure, the WVP of the films varies and remains constant when the relative humidity (RH) is >84%. Equilibrium sorption isotherms of these films have been measured; the Guggenheim-Anderson-de Boer (GAB) model was used to describe the sorption isotherm and contributed to a better knowledge of hydration properties. Surface hydrophobicity and wettability of these films were also investigated using the sessile drop contact angle method. The results obtained suggested the migration of the lipid fraction toward evaporation surface during film drying. Among these polysaccharide-based films, AG-based film and CAS-based film displayed more interesting mechanical properties: they are transparent, clear, homogeneous, flexible, and easily handled. NRS- and WRS-based films were relatively brittle and have a low tension resistance. Microstructure of film cross section was observed by environmental scanning electron microscopy to better understand the effect of the structure on the functional properties. The results suggest that AG-based film and CAS-based films, which show better functional properties, are promising systems to be used as food packaging or coating instead of NRS- and WRS-based films.

  8. Influence of phosphate on phytotoxicity of ceria nanoparticles in an agar medium.

    Science.gov (United States)

    Wang, Guohua; Ma, Yuhui; Zhang, Peng; He, Xiao; Zhang, Zhaohui; Qu, Meihua; Ding, Yayun; Zhang, Junzhe; Xie, Changjian; Luo, Wenhe; Zhang, Jing; Chu, Shengqi; Chai, Zhifang; Zhang, Zhiyong

    2017-05-01

    Fate and toxicity of manufactured nanoparticles (NPs) in the living organisms and the environment are highly related to their transformation. In the present study, the effect of phosphate on the phytotoxicity and transformation of CeO 2 NPs was investigated in an agar medium using head lettuce plants that are sensitive to Ce 3+ ions. Plants were treated by CeO 2 NPs with or without phosphate for 10 days. Results suggest that the treatments of P deficiency (P(-)) and CeO 2 NPs (P(+)&Ce) could separately induce significant inhibition on the growth of lettuce seedlings and cause oxidative stress, but the inhibition was the most serious when the two conditions were combined (P(-)&Ce). In the absence of phosphate, more CeO 2 NPs were transformed to Ce(III) in the roots and more Ce 3+ ions were translocated to the shoots, which induced higher toxicity to head lettuce. Phosphates could alleviate the phytotoxic effect of CeO 2 NPs through the precipitation of dissociated Ce 3+ ions. Considering the wide existence of phosphate in the environment, phosphate-related transformation may be a critical factor in evaluating the toxicity and fate of many other metal-based NPs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Dense and Cellular Zirconia Produced by Gel Casting with Agar: Preparation and High Temperature Characterization

    Directory of Open Access Journals (Sweden)

    Jean-Marc Tulliani

    2013-01-01

    Full Text Available A modified gel-casting process was developed to produce both dense and highly porous (40% volume yttria tetragonal zirconia polycrystal (Y-TZP using agar, a natural polysaccharide, as gelling agent. A fugitive phase, made of commercial polyethylene spheres, was added to the ceramic suspension before gelling to produce cellular ceramic structures. The characterization of the microstructural features of both dense and cellular ceramics was carried out by FEG SEM analysis of cross-sections produced by focused ion beam. The mechanical properties of the components were characterized at room temperature by nanoindentation tests in continuous stiffness measurement mode, by investigating the direct effect of the presence of residual microporosity. The presence of a diffuse residual microporosity from incomplete gel deaeration resulted in a decay of the bending strength and of the elastic modulus. The mechanical behavior of both dense and cellular zirconia (in terms of elastic modulus, flexural strength, and deformation at rupture was investigated by performing four-point bending tests at the temperature of 1500°C.

  10. Antimicrobial susceptibility of Brazilian Clostridium difficile strains determined by agar dilution and disk diffusion

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    Edmir Geraldo Fraga

    2016-09-01

    Full Text Available Clostridium difficile is a leading cause of diarrhea in hospitalized patients worldwide. While metronidazole and vancomycin are the most prescribed antibiotics for the treatment of this infection, teicoplanin, tigecycline and nitazoxanide are alternatives drugs. Knowledge on the antibiotic susceptibility profiles is a basic step to differentiate recurrence from treatment failure due to antimicrobial resistance. Because C. difficile antimicrobial susceptibility is largely unknown in Brazil, we aimed to determine the profile of C. difficile strains cultivated from stool samples of inpatients with diarrhea and a positive toxin A/B test using both agar dilution and disk diffusion methods. All 50 strains tested were sensitive to metronidazole according to CLSI and EUCAST breakpoints with an MIC90 value of 2 μg/mL. Nitazoxanide and tigecycline were highly active in vitro against these strains with an MIC90 value of 0.125 μg/mL for both antimicrobials. The MIC90 were 4 μg/mL and 2 μg/mL for vancomycin and teicoplanin, respectively. A resistance rate of 8% was observed for moxifloxacin. Disk diffusion can be used as an alternative to screen for moxifloxacin resistance, nitazoxanide, tigecycline and metronidazole susceptibility, but it cannot be used for testing glycopeptides. Our results suggest that C. difficile strains from São Paulo city, Brazil, are susceptible to metronidazole and have low MIC90 values for most of the current therapeutic options available in Brazil.

  11. Cytotoxicity of alloying elements and experimental titanium alloys by WST-1 and agar overlay tests.

    Science.gov (United States)

    Song, Yo-Han; Kim, Min-Kang; Park, Eun-Jin; Song, Ho-Jun; Anusavice, Kenneth J; Park, Yeong-Joon

    2014-09-01

    This study was performed to evaluate the biocompatibility of nine types of pure metals using 36 experimental prosthetic titanium-based alloys containing 5, 10, 15, and 20wt% of each substituted metal. The cell viabilities for pure metals on Ti alloys that contain these elements were compared with that of commercially pure (CP) Ti using the WST-1 test and agar overlay test. The ranking of pure metal cytotoxicity from most potent to least potent was: Co>Cu>In>Ag>Cr>Sn>Au>Pd>Pt>CP Ti. The cell viability ratios for pure Co, Cu, In, and Ag were 13.9±4.6%, 21.7±10.4%, 24.1±5.7%, and 24.8±6.0%, respectively, which were significantly lower than that for the control group (pcytotoxic', whereas all Ti alloys were ranked as 'noncytotoxic'. The cytotoxicity of pure Ag, Co, Cr, Cu, and In suggests a need for attention in alloy design. The cytotoxicity of alloying elements became more biocompatible when they were alloyed with titanium. However, the cytotoxicity of titanium alloys was observed when the concentration of the alloying element exceeded its respective allowable limit. The results obtained in this study can serve as a guide for the development of new Ti-based alloy systems. Copyright © 2014 Academy of Dental Materials. All rights reserved.

  12. Elemental composition of Physarum compressum Alb. et Schw. sporocarps and their structures cultivated on rabbit dung and agar substrates.

    Science.gov (United States)

    Janik, Paulina; Tylko, Grzegorz; Ostachowicz, Beata; Turnau, Katarzyna

    2010-12-01

    The elemental composition of spores, peridium walls, and lime nodes of Physarum compressum sporocarps, cultivated on rabbit dung as a natural growing environment for the slime mold and on artificial agar medium, was compared to evaluate differences that may be dependent on substrates. Whole fruiting bodies and samples of both experimental media were extracted with nitric acid or Parr digest bomb, respectively, and analyzed by means of total X-ray reflection fluorescence (TXRF). Electron probe microanalysis (EPMA) of spores, peridium walls, and lime nodes structure was carried out with the scanning electron microscope equipped with energy-dispersive spectrometer. Because of minute sizes and roughness of investigated structures, Monte Carlo simulations were utilized to establish analytical conditions of EPMA. Biological and geological standards were used in the quantification of element concentrations. According to TXRF, the fruiting bodies from agar medium revealed lower concentrations of K, Ca, Cr, Mn, and Fe in relation to fruiting bodies from the dung, reflecting elemental relationships in the experimental media. According to EPMA, the highest Ca concentration was found in the lime nodes followed by the peridium and the spores. Culturing of the slime molds on the rabbit dung indicated higher concentration of Ca in the lime nodes and peridium walls when compared with those obtained from the sporocarps grown on agar media. The opposite relation was found for the spores. The concentration of Na, Mg, P, S, and Cl was generally lower in all structures of the sporocarps harvested from the dung than from the agar medium. K was in higher concentration in analyzed structures from dung than from agar. Different element uptake (except for Ca and K) was revealed by the two methods: TXRF and EPMA.

  13. Comparison of sorbitol MacConkey and hemorrhagic coli agars for recovery of Escherichia coli O157:H7 from brie, ice cream, and whole milk.

    Science.gov (United States)

    Hammack, T S; Feng, P; Amaguaña, R M; June, G A; Sherrod, P S; Andrews, W H

    1997-01-01

    The relative efficacies of hemorrhagic coli (HC) agar and several formulations of sorbitol MacConkey (SorMac) agar, with and without 0.1% (w/v) 4-methyllumbelliferyl-beta-D-glucuronide (MUG), in recovering unstressed and heat-stressed Escherichia coli O157:H7 from Brie cheese, ice cream, and whole milk were determined. Recovery of unstressed E. coli O157:H7 was determined quantitatively by spread-plating diluted samples onto different agars and performing plate counts. Recovery of stressed E. coli O157:H7 was determined qualitatively by enriching samples in modified trypticase soy broth, streaking the incubated enrichments, and isolating E. coli O157:H7 colonies from the agars. HC agar and the SorMac agar formulations did not differ significantly in their ability to recover unstressed E. coli O157:H7 from ice cream and whole milk; however, HC agar recovered significantly more unstressed E. coli O157:H7 from Brie cheese than did the SorMac agar formulations. Bacteriological Analytical Manual and Oxoid SorMac agar formulations made from individual ingredients, did not differ significantly in recovering unstressed E. coli O157:H7 from Brie cheese. The efficiency of the commercially available Oxoid SorMac agar could not be determined because of overgrowth by indigenous microflora. HC and SorMac agars did not differ significantly in recovering stressed E. coli O157:H7 from Brie cheese, ice cream, and whole milk. MUG had no apparent effect on recovery of either stressed or unstressed E. coli O157:H7 from the dairy foods examined.

  14. Desenvolvimento de uma reação em cadeia pela polimerase e comparação com a imunodifusão em gel de agar na detecção de infecções pelo vírus da leucemia bovina

    Directory of Open Access Journals (Sweden)

    Marcelo Fernandes Camargos

    2003-01-01

    Full Text Available A reação em cadeia pela polimerase (PCR foi utilizada para a detecção do vírus da leucemia bovina (VLB em leucócitos periféricos de bovinos infectados. Os iniciadores utilizados foram construídos para amplificar uma parte do gene env do VLB. Os produtos da PCR foram analisados por eletroforese em gel de agarose corados por brometo de etídeo. A especificidade analítica da PCR foi confirmada por restrição enzimática dos produtos da reação com Bam HI e também pela análise da seqüência de três amostras. Sessenta e cinco animais foram testados para a presença de anticorpos anti-VLB, pela imunodifusão em gel de agar (IDGA e pela PCR, para detecção direta do VLB. Houve 73,80% de concordância entre os dois testes. Quatro animais positivos na IDGA foram PCR negativos, enquanto 13 animais negativos na IDGA foram positivos na PCR. A sensibilidade diagnóstica obtida foi de 0,87 e a especificidade diagnóstica 0,62. A PCR desenvolvida pode ser uma ferramenta complementar no diagnóstico de infecções causadas pelo VLB, mas deve ter sua sensibilidade diagnóstica melhorada.

  15. Use of agar diffusion assay to evaluate bactericidal activity of formulations of alkaline salts of fatty acids against bacteria associated with poultry processing

    Science.gov (United States)

    The agar diffusion assay was used to examine antibacterial activity of alkaline salts of fatty acids (FA). Wells in agar media seeded with bacteria were filled with FA-potassium hydroxide (KOH) solutions, plates were incubated, and zones of inhibition were measured. The relationship between bacteric...

  16. Comparison of Rosco Neo-Sensitabs with Oxoid paper disks in EUCAST disk diffusion antimicrobial susceptibility testing on Mueller-Hinton agar

    DEFF Research Database (Denmark)

    Justesen, U S; Acar, Ziyap; Olsson, K

    2013-01-01

    This study compared Neo-Sensitabs with Oxoid paper disks using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) disk diffusion antimicrobial susceptibility test on Mueller-Hinton agar. The EUCAST-recommended quality control strains (Escherichia coli ATCC 25922, Pseudomonas...... paper disks for EUCAST disk diffusion antimicrobial susceptibility testing on Mueller-Hinton agar....

  17. Cylindrical agar gel with fluid flow subjected to an alternating magnetic field during hyperthermia.

    Science.gov (United States)

    Javidi, Mehrdad; Heydari, Morteza; Attar, Mohammad Mahdi; Haghpanahi, Mohammad; Karimi, Alireza; Navidbakhsh, Mahdi; Amanpour, Saeid

    2015-02-01

    In magnetic fluid hyperthermia (MFH), nanoparticles are injected into diseased tissue and subjected to an alternating high frequency magnetic field. The process triggers sufficient heat to destroy the cancerous cells. One of the challenging problems during MFH is blood flow in tissue. In real conditions the heat which is transferred by blood flow should be considered in the analysis of MFH. In this study, heat transfer was investigated in an agar gel phantom containing fluid flow. Fe3O4 as a nano-fluid was injected into the centre of a gel cylinder which was filled with another gel cylinder and subjected to an alternating magnetic field of 7.3 kA/m and a frequency of 50 kHz for 3600 s. The temperature was measured at three points in the gel. Temperature distributions regarding the time at these three points were experimentally measured. Moreover, the specific absorption rate (SAR) function was calculated with a temperature function. The SAR function was a key asset in the hyperthermia and was obtained on the condition that the fluid flowed through the gel. Finally, a finite element analysis (FEA) was performed to verify the SAR function. The results revealed that there was good agreement between the measured temperature and the one obtained from FEA. In addition, the effects of fluid flow and accuracy of function obtained for heat production in the gel were presented. It is believed that the proposed model has the potential ability to get close to reality in this type of investigation. The proposed function has implications for use in further modelling studies as a heat generation source.

  18. Effect of orientational ordering of magnetic nanoemulsions immobilized in agar gel on magnetic hyperthermia

    Science.gov (United States)

    Lahiri, B. B.; Ranoo, Surojit; Philip, John

    2018-04-01

    Magnetic nanoemulsions of droplet size ∼200 nm, loaded with single domain superparamagnetic nanoparticles (MNP), are potential candidates for multimodal hyperthermia due to availability of large loading volume and enhanced permeation and retention (EPR) in the cancerous tissues. In such nanoemulsions, radio frequency alternating magnetic field induced heating occur at two entirely different length scales, viz. Neel-Brown relaxation of the dispersed MNP and Brownian relaxation of emulsion droplets. Here we study the effects of orientation ordering or texturing of droplets, immobilized in a tissue mimicking agar matrix, on the field induced heating efficiency. A higher specific absorption rate (maximum ∼73 ± 2 W/gFe) is observed for droplets orientated parallel to the direction of the alternating magnetic field because of the enhancement of effective uniaxial anisotropy energy density and increased effective relaxation time. For identical and non-interacting MNP oriented parallel to the external DC magnetic field, a threefold increase in the effective uniaxial anisotropy energy density and ∼20-30% increased specific absorption rate are observed as compared to those oriented perpendicular to the magnetic field. Magnetic force microscopy images showed that the spherical morphology of the droplets remains intact even after orientational ordering and average topographic height of the droplets are found to be ∼220 (±17) nm, which is in good agreement with the most probable size obtained from dynamic light scattering. The residual volume magnetization of the emulsion droplets is found to be 1.1 × 10-6 emu/cc, indicating the superparamagnetic nature of the droplets in tissue equivalent environment. The observed increase in heating efficiency of the immobilized and oriented emulsion droplets shows promising applications in multimodal hyperthermia therapy because of the requirement of lower dose of MNP and shorter treatment time.

  19. Evaluation of semisolid agar method for antifungal susceptibility test of T. rubrum

    Directory of Open Access Journals (Sweden)

    Sultana Razia

    2016-08-01

    Full Text Available Background: With increasing fungal disease many newer antifungal drugs are available with different spectrum of activ­ity. Antifungal susceptibility test will help clinicians for selection of effective drug and thereby treatment of patient. Objective: The study was undertaken to perform a simple screening drug susceptibility test of T. rnbrum by Semi Solid Agar Antifungal Susceptibility (SAAS Method: Perfonnance of susceptibility method was assessed by comparing the MICs of three commonly prescribed antifungal agents namely- tluconazole (FCZ, itraconazole (ITZ and terbinafine (TER to the CLSI (Clinical and Laboratory Standard Institute recommended M-38, a broth microdilution method. Results: In SAAS method, among twenty nine T. rubrum, twenty five (86.2% were susceptible (MIC range 0.5-64 µg/ml to Fluconazole (FCZ and four (13.7% were resistant (MIC value >64 µg/ml. In broth microdilution method, among twenty nine T. rubrum, twenty six (89.6% were susceptible (MIC range 0.3-64 µg/ml to FCZ and three (10.3% were resistant (MIC value >64 µg/ml. In case of both ITZ and TER, all were susceptible (MIC range 0.3-64 µg/ml to both methods. The SAAS method demonstrated the susceptibility pattern of T. rubrum against FCZ, ITZ and TER usually within 72 to 96 hours after organism isolation and results were concordance with the results of CLSI broth microdilution method. Conclusion: Though it is a newer method with proper standardization of the test method, SAAS method is simple and easily applicable screening method for susceptibility testing of antifungal agents against dermatophytes in any microbiology laboratories.

  20. Preparation and application of agar/alginate/collagen ternary blend functional food packaging films.

    Science.gov (United States)

    Wang, Long-Feng; Rhim, Jong-Whan

    2015-09-01

    Ternary blend agar/alginate/collagen (A/A/C) hydrogel films with silver nanoparticles (AgNPs) and grapefruit seed extract (GSE) were prepared. Their performance properties, transparency, tensile strength (TS), water vapor permeability (WVP), water contact angle (CA), water swelling ratio (SR), water solubility (WS), and antimicrobial activity were determined. The A/A/C film was highly transparent, and both AgNPs and GSE incorporated blend films (A/A/C(AgNPs) and A/A/C(GSE)) exhibited UV-screening effect, especially, the A/A/C(GSE) film had high UV-screening effect without sacrificing the transmittance. In addition, the A/A/C blend films formed efficient hydrogel film with the water holding capacity of 23.6 times of their weight. Both A/A/C(AgNPs) and A/A/C(GSE) composite films exhibited strong antimicrobial activity against both Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli) food-borne pathogenic bacteria. The test results of fresh potatoes packaging revealed that all the A/A/C ternary blend films prevented forming of condensed water on the packaged film surface, both A/A/C(AgNPs) and A/A/C(GSE) composite films prevented greening of potatoes during storage. The results indicate that the ternary blend hydrogel films incorporated with AgNPs or GSE can be used not only as antifogging packaging films for highly respiring fresh agriculture produce, but also as an active food packaging system utilizing their strong antimicrobial activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Pump apparatus including deconsolidator

    Energy Technology Data Exchange (ETDEWEB)

    Sonwane, Chandrashekhar; Saunders, Timothy; Fitzsimmons, Mark Andrew

    2014-10-07

    A pump apparatus includes a particulate pump that defines a passage that extends from an inlet to an outlet. A duct is in flow communication with the outlet. The duct includes a deconsolidator configured to fragment particle agglomerates received from the passage.

  2. Electro-driven extraction of polar compounds using agarose gel as a new membrane: Determination of amino acids in fruit juice and human plasma samples.

    Science.gov (United States)

    Sedehi, Samira; Tabani, Hadi; Nojavan, Saeed

    2018-03-01

    In this work, polypropylene hollow fiber was replaced by agarose gel in conventional electro membrane extraction (EME) to develop a novel approach. The proposed EME method was then employed to extract two amino acids (tyrosine and phenylalanine) as model polar analytes, followed by HPLC-UV. The method showed acceptable results under optimized conditions. This green methodology outperformed conventional EME, and required neither organic solvents nor carriers. The effective parameters such as the pH values of the acceptor and the donor solutions, the thickness and pH of the gel, the extraction voltage, the stirring rate, and the extraction time were optimized. Under the optimized conditions (acceptor solution pH: 1.5; donor solution pH: 2.5; agarose gel thickness: 7mm; agarose gel pH: 1.5; stirring rate of the sample solution: 1000rpm; extraction potential: 40V; and extraction time: 15min), the limits of detection and quantification were 7.5ngmL -1 and 25ngmL -1 , respectively. The extraction recoveries were between 56.6% and 85.0%, and the calibration curves were linear with correlation coefficients above 0.996 over a concentration range of 25.0-1000.0ngmL -1 for both amino acids. The intra- and inter-day precisions were in the range of 5.5-12.5%, and relative errors were smaller than 12.0%. Finally, the optimized method was successfully applied to preconcentrate, clean up, and quantify amino acids in watermelon and grapefruit juices as well as a plasma sample, and acceptable relative recoveries in the range of 53.9-84.0% were obtained. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Agarose gel electrophoresis of joint fluid using Hyrys-Hydrasys SEBIA system as a new prognostic tool for periprosthetic osteolysisin revision arthroplasty

    Science.gov (United States)

    Chiva, A

    2013-01-01

    Rationale. Prevention of wear-mediated osteolysis, the most common complication in total joint arthroplasty, is a great challenge for orthopedic surgery. Despite the diversity of current biomarkers of periprosthetic osteolysis (products of wear, bone turnover and inflammatory biomarkers), the major interferences and the great amount of sample necessary for analysis limit their use in clinical practice. Objective. The aim of this paper is to present three new electrophoretic methods using Hyrys-Hydrasys SEBIA system that have been used for the first time in Electrophoresis Laboratory of our hospital in the analysis of joint fluid for the prevention of periprosthetic osteolysis in revision arthroplasty. Methods and results. Analytical aspects of agarose gel electrophoresis of joint fluid proteins and lipoproteins as well as SDS-agarose gel electrophoresis of joint fluid proteins, their performances and clinical value are presented. The decreased level of albumin and increased level of alpha1 and alpha2 globulins were frequent changes detected on SEBIA electropherograms and good indicator for the presence of an inflammatory reaction generated by particle debris. In addition, a slightly increase of LDL mobility could provide good information about a high oxidative stress. Moreover, the Ig G assessed by using SDS-agarose gel electrophoresis could be a potential biomarker for an immunological reaction towards orthopedic implants. Discussion. Electrophoresis of joint fluid using Hyrys-Hydrasys SEBIA France system is a new analytical technique able to remove the most of current biomarkers disadvantages due to the determination of particular proteins (acute phase proteins, albumin, lipoproteins, and immunoglobulins) by using minimal amounts of joint fluid with minor interferences, minimal cost and rapid results. Abbreviations CTX, crosslinked C-telopeptide; IL- interleukins; Ig G, immunoglobulin G; LDL, low density lipoprotein; NTX, crosslinked N-telopeptide; PICP

  4. Optical modulator including grapene

    Science.gov (United States)

    Liu, Ming; Yin, Xiaobo; Zhang, Xiang

    2016-06-07

    The present invention provides for a one or more layer graphene optical modulator. In a first exemplary embodiment the optical modulator includes an optical waveguide, a nanoscale oxide spacer adjacent to a working region of the waveguide, and a monolayer graphene sheet adjacent to the spacer. In a second exemplary embodiment, the optical modulator includes at least one pair of active media, where the pair includes an oxide spacer, a first monolayer graphene sheet adjacent to a first side of the spacer, and a second monolayer graphene sheet adjacent to a second side of the spacer, and at least one optical waveguide adjacent to the pair.

  5. SYBR Green I staining of pulsed field agarose gels is a sensitive and inexpensive way of quantitating DNA double-strand breaks in mammalian cells.

    Science.gov (United States)

    Kiltie, A E; Ryan, A J

    1997-07-15

    Pulsed field gel electrophoresis (PFGE) is widely used to measure DNA double strand breaks (dsb). The DNA of cultured cells can be prelabelled with radioactivity, which helps greatly in detection and quantitation of DNA dsb. However, this approach cannot be used with non-cycling cells from biopsy material. We describe a method which uses SYBR Green I to stain DNA in dried agarose gels. DNA is detected and analysed using readily available camera equipment and image analysis software. This method is as sensitive as [3H]thymidine prelabelling of cells and allows DNA dsb to be measured simply and economically in non-cycling cells.

  6. A subtle calculation method for nanoparticle’s molar extinction coefficient: The gift from discrete protein-nanoparticle system on agarose gel electrophoresis

    Science.gov (United States)

    Zhong, Ruibo; Yuan, Ming; Gao, Haiyang; Bai, Zhijun; Guo, Jun; Zhao, Xinmin; Zhang, Feng

    2016-03-01

    Discrete biomolecule-nanoparticle (NP) conjugates play paramount roles in nanofabrication, in which the key is to get the precise molar extinction coefficient of NPs. By making best use of the gift from a specific separation phenomenon of agarose gel electrophoresis (GE), amphiphilic polymer coated NP with exact number of bovine serum albumin (BSA) proteins can be extracted and further experimentally employed to precisely calculate the molar extinction coefficient of the NPs. This method could further benefit the evaluation and extraction of any other dual-component NP-containing bio-conjugates.

  7. Validation of a quantitative real-time PCR assay and comparison with fluorescence microscopy and selective agar plate counting for species-specific quantification of an in vitro subgingival biofilm model.

    Science.gov (United States)

    Ammann, T W; Bostanci, N; Belibasakis, G N; Thurnheer, T

    2013-08-01

    Subgingival biofilms are the prime etiological factor of periodontal disease. Owing to their complex polymicrobial nature, quantification of individual bacterial species within the biofilm for research and diagnostic purposes can be methodologically challenging. The aims of this study were to establish a quantitative real-time PCR (qPCR) assay to quantify the bacteria used in our 10-species in vitro 'subgingival' biofilm model and to compare the quantitative outcome with fluorescence microscopy and colony-forming unit (CFU) counts on selective agar plates. The 10 species included in the in vitro biofilm were Streptococcus oralis, Streptococcus anginosus, Veillonella dispar, Fusobacterium nucleatum, Treponema denticola, Tannerella forsythia, Actinomyces oris, Campylobacter rectus, Porphyromonas gingivalis and Prevotella intermedia. The numbers of each species were quantified at two time points using qPCR, microscopy counting following fluorescence in-situ hybridization (FISH) or immunofluorescence staining, and counting of CFUs after growth on selective agar plates. All 10 species were successfully quantified using qPCR and FISH or immunofluorescence, and the eight species culturable on selective agar plates were also quantified by counting the numbers of CFUs after growth on selective agar. In early biofilm cultures, all methods showed a significant correlation, although the absolute numbers differed between methods. In late biofilm cultures, measurements obtained using qPCR and FISH or immunofluorescence, but not by CFU counts, maintained significant correlation. CFU counts yielded lower values than did measurements made using the other two methods. Quantitative PCR and epifluorescence microscopy can be easily combined with each other to determine species-specific bacterial numbers within biofilms. However, conventional bacterial cultures cannot be as efficiently combined using these molecular detection methods. This may be crucial in designing and selecting

  8. Effect of EDTA on Pb(II) Uptake and Translocation by Tumbleweed (Salsola Kali): Agar and Hydroponics Studies

    Energy Technology Data Exchange (ETDEWEB)

    de la Rosa, Guadalupe; Gardea-Torresdey, Jorge L.; Peralta-Videa, Jose R.; Aldrich, Mary

    2004-03-31

    Environmental accumulation of Pb represents a worldwide health hazard. While conventional cleanup techniques are generally expensive and soil disturbing, phytoremediation represents an inexpensive friendly option for the removal of contaminants from soil and water. In this research, tumbleweed (Salsola kali) plants exposed for 15 days to Pb(NO3)2 at 80 and 125 ppm in hydroponics and agar media, demonstrated a high capacity to uptake lead. The results showed that the plants cultivated in agar accumulated 25563, 5534 and 2185 mg Pb kg-1 DW in roots, stems and leaves, respectively. Moreover, Pb concentrations found in hydroponically grown tumbleweed plants tissues were 30744, 1511 and 1421 mg kg-1 DW in roots, stems and leaves, respectively. It was observed that EDTA enhanced Pb translocation. No Pb phytotoxic effects were observed during the experimental time period. Cellular structural features were also observed using TEM.

  9. The effect of different brands of MacConkey and xylose lysine deoxycholate agar on the isolation of Aeromonas hydrophila.

    Science.gov (United States)

    Tsai, W C; Chu, S H; Lee, S Y; Lee, P F

    1987-08-01

    Aeromonas hydrophila has been reported to be involved in the opportunistic infection of human beings, therefore, its rapid diagnosis from the clinical specimens was considered to be extremely important for the prognosis. The effect of different brands of MacConkey (MAC) and xylose lysine deoxycholate (XLD) agars on the plating efficiency and colony size of A. hydrophila was evaluated by comparing with blood agar. Results indicate that (i) except Eiken's MAC have low plating efficiency, all the MAC from BBL, Difco, Mast, Merck, and Gibco have good plating efficiency; (ii) except Eiken's and Gibco XLD, all XLD from Difco, Mast, and Merck have larger bacterial colony size; and (iii) colonies of A. hydrophila appeared on MAC are larger than those on XLD of the same brands. We suggested that a clinical laboratory microbiologist should be alert in selecting the appropriate media to isolate the clinically important bacteria.

  10. Isolation of Shiga Toxin-Producing Escherichia coli from Ground Beef Using Multiple Combinations of Enrichment Broths and Selective Agars.

    Science.gov (United States)

    Brusa, Victoria; Piñeyro, Pablo E; Galli, Lucía; Linares, Luciano H; Ortega, Emanuel E; Padola, Nora L; Leotta, Gerardo A

    2016-03-01

    Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens, and beef cattle are recognized as the principal reservoir. The aims of this study were (1) to identify the most sensitive combination of selective enrichment broths and agars for STEC isolation in artificially inoculated ground beef samples, and (2) to evaluate the most efficient combination(s) of methods for naturally contaminated ground beef samples. A total of 192 ground beef samples were artificially inoculated with STEC and non-stx bacterial strains. A combination of four enrichment broths and three agars were evaluated for sensitivity, specificity, and positive predictive value for STEC isolation from experimentally inoculated samples. Enrichments with either modified tryptic soy broth (mTSB) containing 8 mg/L novobiocin (mTSB-8) or modified Escherichia coli (mEC) broth followed by isolation in MacConkey agar were the most sensitive combinations for STEC isolation of artificially inoculated samples. Independently, both enrichments media followed by isolation in MacConkey were used to evaluate ground beef samples from 43 retail stores, yielding 65.1% and 58.1% stx-positive samples by RT-PCR, respectively. No difference was observed in the isolate proportions between these two methods (8/25 [32%] and 8/28 [28.6%]). Identical serotypes and stx genotypes were observed in STEC strains isolated from the same samples by either method. In this study, no single enrichment protocol was sufficient to detect all STEC in artificially inoculated samples and had considerable variation in detection ability with naturally contaminated samples. Moreover, none of the single or combinations of multiple isolation agars used were capable of identifying all STEC serogroups in either artificially inoculated or naturally occurring STEC-contaminated ground beef. Therefore, it may be prudent to conclude that there is no single method or combination of isolation methods capable of identifying all STEC serogroups.

  11. Comparison of antibacterial activities of root-end filling materials by an agar diffusion assay and Alamar blue assay

    Directory of Open Access Journals (Sweden)

    Tsui-Hsien Huang

    2012-12-01

    Conclusion: We concluded that both the agar diffusion test and Alamar blue assay gave comparable findings of assessing the antimicrobial activity present in root-end filling materials. No antimicrobial activity was detected for mineral trioxide aggregate, calcium silicate cement, or amalgam after coming into contact with S. mutans, S. sanguinis and E. coli. IRM showed high antimicrobial activity against both S. sanguinis and E. coli.

  12. Comparative studies on structural feature of agar polysaccharides from Porphyra haitanensis grown in south and north China

    Science.gov (United States)

    Hongfeng, Gao; Minghou, Ji; Wenda, Cao

    1993-03-01

    The structural feature of agar polysaccharides from Porphyra haitanensis grown in south China and transplanted to the north was investigated by fractionation on DEAE—Sephadex A 50, chemical analysis, and infrared and13C-NMR spectroscopy. The agars composed mainly of charged molecules were eluted from DEAE—Sephadex A 50 with 1.0 mol/L NaCl solution from the southern P. haitanensis and with 0.5 mol/L NaCl from the northern one. The13C-NMR spectra showed that agarobiose [(1→3)-β- D-galactopyranosyl-(1→4)-3,6-anhydro-α- L-galactopyranose] and the biological precursor of agarobiose [(1→3)-β- D-galactopyra nosyl-(1→4)-6-sulfate-α- L-galactopyranose] were the major disaccharide repeating units in the charged fractions. The content of the biological precursor in the agar polysaccharides from southern P. haitanensis was higher than that in the northern one, the content of the biological precursor extracted from cold water was higher than that from hot water, and the content of 6-OMe- D-galactose in the southern P. haitanensis polysaccharides was higher than in the northern one. This distinct difference will be of significance for further study of the physiological characters of P. haitanensis.

  13. Evaluation of the Morphology and Biocompatibility of Natural Silk Fibers/Agar Blend Scaffolds for Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    Luong Thu-Hien

    2018-01-01

    Full Text Available This study was aimed to develop a tissue engineering scaffold by incorporation of Bombyx mori silk fiber (BMSF and agar. This promised the improvement in enhancing their advantageous properties as well as limiting their defects without occurring chemical reactions or crosslink formation. The morphology and chemical structure of scaffolds were observed using scanning electron microscope (SEM observation and Fourier transform infrared (FT-IR spectra. The SEM results show that scaffolds containing BMSF have microporous structures, which are suitable for cell adhesion. Agar scaffolds, by contrast, had much more flat morphology. FT-IR spectra confirm that no modifications to BMSF happened in scaffolds, which indicates that there was no chemical reaction or crosslink formation between silk and agar in this process. Furthermore, the biocompatibility of scaffolds was performed in the mouse’s subcutaneous part of the dorsal region for 15 days, followed by Haematoxylin and Eosin (H&E staining. H&E staining results demonstrate that scaffolds had good biocompatibility and there was no sign of the body rejection in all of samples. The results from animal study show that SA scaffolds have the most stable structure for cell adhesion compared with those single materials.

  14. Mechanical touch responses of Arabidopsis TCH1-3 mutant roots on inclined hard-agar surface

    Science.gov (United States)

    Zha, Guodong; Wang, Bochu; Liu, Junyu; Yan, Jie; Zhu, Liqing; Yang, Xingyan

    2016-01-01

    The gravity-induced mechanical touch stimulus can affect plant root architecture. Mechanical touch responses of plant roots are an important aspect of plant root growth and development. Previous studies have reported that Arabidopsis TCH1-3 genes are involved in mechano-related events, how-ever, the physiological functions of TCH1-3 genes in Arabidopsis root mechanoresponses remain unclear. In the present study, we applied an inclined hard agar plate method to produce mechanical touch stimulus, and provided evidence that altered mechanical environment could influence root growth. Furthermore, tch1-3 Arabidopsis mutants were investigated on inclined agar surfaces to explore the functions of TCH1-3 genes on Arabidopsis root mechanoresponses. The results showed that two tch2 mutants, cml24-2 and cml24-4, exhibited significantly reduced root length, biased skewing, and decreased density of lateral root. In addition, primary root length and density of lateral root of tch3 (cml12-2) was significantly decreased on inclined agar surfaces. This study indicates that the tch2 and tch3 mutants are hypersensitive to mechanical touch stimulus, and TCH2 (CML24-2 and CML24-4) and TCH3 (CML12-2) genes may participate in the mechanical touch response of Arabidopsis roots.

  15. Nutrient limitation leads to penetrative growth into agar and affects aroma formation in Pichia fabianii, P. kudriavzevii and Saccharomyces cerevisiae.

    Science.gov (United States)

    van Rijswijck, Irma M H; Dijksterhuis, Jan; Wolkers-Rooijackers, Judith C M; Abee, Tjakko; Smid, Eddy J

    2015-01-01

    Among fermentative yeast species, Saccharomyces cerevisiae is most frequently used as a model organism, although other yeast species may have special features that make them interesting candidates to apply in food-fermentation processes. In this study, we used three yeast species isolated from fermented masau (Ziziphus mauritiana) fruit, S. cerevisiae 131, Pichia fabianii 65 and Pichia kudriavzevii 129, and determined the impact of nitrogen and/or glucose limitation on surface growth mode and the production of volatile organic compounds (VOCs). All three species displayed significant changes in growth mode in all nutrient-limited conditions, signified by the formation of metafilaments or pseudohyphae. The timing of the transition was found to be species-specific. Transition in growth mode is suggested to be linked to the production of certain fusel alcohols, such as phenylethyl alcohol, which serve as quorum-sensing molecules. Interestingly, we did not observe concomitant increased production of phenylethyl alcohol and filamentous growth. Notably, a broader range of esters was found only for the Pichia spp. grown on nitrogen-limited agar for 21 days compared to nutrient-rich agar, and when grown on glucose- and glucose- plus nitrogen-limited agar. Our data suggest that for the Pichia spp., the formation of esters may play an important role in the switch in growth mode upon nitrogen limitation. Further biological or ecological implications of ester formation are discussed. Copyright © 2014 John Wiley & Sons, Ltd.

  16. Enhanced Agarose and Xylan Degradation for Production of Polyhydroxyalkanoates by Co-Culture of Marine Bacterium, Saccharophagus degradans and Its Contaminant, Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Shailesh S. Sawant

    2017-02-01

    Full Text Available Over reliance on energy or petroleum products has raised concerns both in regards to the depletion of their associated natural resources as well as their increasing costs. Bioplastics derived from microbes are emerging as promising alternatives to fossil fuel derived petroleum plastics. The development of a simple and eco-friendly strategy for bioplastic production with high productivity and yield, which is produced in a cost effective manner utilising abundantly available renewable carbon sources, would have the potential to result in an inexhaustible global energy source. Here we report the biosynthesis of bioplastic polyhydroxyalkanoates (PHAs in pure cultures of marine bacterium, Saccharophagus degradans 2-40 (Sde 2-40, its contaminant, Bacillus cereus, and a co-culture of these bacteria (Sde 2-40 and B. cereus degrading plant and algae derived complex polysaccharides. Sde 2-40 degraded the complex polysaccharides agarose and xylan as sole carbon sources for biosynthesis of PHAs. The ability of Sde 2-40 to degrade agarose increased after co-culturing with B. cereus. The association of Sde 2-40 with B. cereus resulted in increased cell growth and higher PHA production (34.5% of dry cell weight from xylan as a carbon source in comparison to Sde 2-40 alone (22.7% of dry cell weight. The present study offers an innovative prototype for production of PHA through consolidated bioprocessing of complex carbon sources by pure and co-culture of microorganisms.

  17. Development of a chamber system for rapid, high yield and cost-effective purification of deoxyribonucleic acid fragments from agarose gel.

    Science.gov (United States)

    Eslami, Gilda; Salehi, Rasoul

    2014-01-01

    There are several methods commonly practicing for deoxyribonucleic acid (DNA) purification from agarose gel. In most laboratories, especially in developing countries, present methods for recovering of DNA fragments from the gel are mostly involved organic solvents. However, manual purification using organic solvents are toxic, labor intensive, time consuming and prone to contamination owing to several handling steps. The above mentioned burdens as well as cost and long time to import them, especially in developing countries, prompted us to design and develop a chamber system for rapid, non-toxic, cost-effective and user friendly device for polymerase chain reaction (PCR) products purification from agarose gel. The device was made from plexiglass plates. After amplification of two fragments of 250 and 850 bp, PCR products were electrophoresed. Subsequently, the desired bands were excised and purified with three method: HiPer Mini chamber, phenol extraction method and spin column procedure. To assess the suitability of the purified DNAs, restriction digestion was applied. Results showed that the yield of recovered DNA in our method was above 95%, whereas the yields obtained with conventional phenol extraction and spin column methods were around 60%. In conclusion, the current method for DNA elution is quick, inexpensive and robust and it does not require the use of toxic organic solvents. In addition, the purified DNA was well has suited for further manipulations such as restriction digestion, ligation, cloning, sequencing and hybridization.

  18. Co-immobilization of cyclohexanone monooxygenase and glucose-6-phosphate dehydrogenase onto polyethylenimine-porous agarose polymeric composite using γ irradiation to use in biotechnological processes

    International Nuclear Information System (INIS)

    Atia, K.S.

    2005-01-01

    The co-immobilization of cyclohexanone monooxygenase (CHMO) and glucose-6-phosphate dehydrogenase (G6PDH) was optimized by completely coating, via covalent immobilization, the surface aldehyde groups of porous agarose (glyoxyl-agarose) with amine groups of polyethylenimine (PEI). The highest immobilization efficiency (∼87%) (activity of enzyme per amount of immobilized enzyme) was obtained with a CHMO/G6PDH ratio 2:1. The effects of different ratios of the support to the amount of enzymes (CHMO:G6PDH=2:1), the optimum incubation pH and the incubation time on the enzymatic activity of the enzymes were determined and found to be 5:1, 8.5 and 30 min, respectively. Subjecting the co-immobilized enzymes to doses of γ-radiation (5-100 kGy) resulted in complete loss in the activity of the free enzymes at a dose of 40 kGy, while the co-immobilized ones showed relatively high resistance to γ-radiation up to a dose of 50 kGy

  19. Detection of mutations using microarrays of poly(C)10-poly(T)10 modified DNA probes immobilized on agarose films

    DEFF Research Database (Denmark)

    Dufva, Hans Martin; Petersen, Jesper; Stoltenborg, M.

    2006-01-01

    Allele-specific hybridization to a DNA microarray call be a useful method for genotyping patient DNA. In this article, we demonstrate that 13- to 17-base oligonucleotides tagged with a poly(T)10-poly(C)10 tail (TC tag), but otherwise unmodified, can be crosslinked by UV light irradiation to an ag......Allele-specific hybridization to a DNA microarray call be a useful method for genotyping patient DNA. In this article, we demonstrate that 13- to 17-base oligonucleotides tagged with a poly(T)10-poly(C)10 tail (TC tag), but otherwise unmodified, can be crosslinked by UV light irradiation...... to an agarose film grafted onto unmodified glass. Microarrays of TC-tagged probes immobilized on the agarose film can be used to diagnose Mutations in the human P-globin gene, which encodes the beta-chains in hemoglobin. Although the probes differed widely regarding inciting point temperature (similar to 20...... degrees C), a single stringency wash still gave sufficiently high discrimination signals between perfect match and mismatch probes to allow robust mutation detection. In all, 270 genotypings were performed on patient materials, and no genotype was incorrectly classified. Quality control experiments...

  20. Development of a L-rhamnose and D-arabitol supplemented MacConkey agar to identify pathogenic Yersinia enterocolitica among environmental Yersinias in swine production wastes.

    Science.gov (United States)

    Shehee, M W; Sobsey, M D

    2004-05-01

    Supplemented MacConkey agar with L-rhamnose and D-arabitol distinguishes pathogenic from environmental strains of Yersinia enterocolitica recovered from swine production wastes. This medium has a sensitivity of 100% and a specificity of 97.4%.

  1. Reliability of the agar based method to assess the production of degradative enzymes in clinical isolates of Candida albicans.

    Science.gov (United States)

    Arantes, Paula Tamião; Sanitá, Paula Volpato; Santezi, Carolina; Barbeiro, Camila de Oliveira; Reina, Bárbara Donadon; Vergani, Carlos Eduardo; Dovigo, Lívia Nordi

    2016-03-01

    The aim of this study was to establish a reproducible protocol using the methodology of hyaline zones around the colonies on specific agar plates for phospholipase and proteinase production. This was an in vitro double-blind experiment, in which the dependent variables were the enzymatic activity measurements (Pz) for the production of phospholipase (Pz-ph) and the production of secreted aspartyl proteinases (Pz-sap). Three independent variables give rise to different measurement protocols. All measurements were carried out at two different moments by four examiners (E1, E2, E3, and E4). The minimum sample size was 30 Candida albicans clinical isolates. Specific agar plates for phospholipase and SAPs production were prepared according the literature. The intra-and inter-examiner reproducibility for each protocol was estimated using the Intraclass Correlation Coefficient (ICC) and its confidence interval (95% CI). Based on the results obtained for both phospholipase and SAPs, there appears to be no consensus on the protocol chosen for each particular examiner. Measuring the colonies in triplicate may be the main factor associated with the increase in measurement accuracy and should therefore take precedence over measuring only one colony. When only one examiner is responsible for taking measurements, a standard protocol should be put in place and the statistical calibration of this researcher should be done prior to data collection. However, if two or more researchers are involved in the assessment of agar plates, our results suggest that the protocols using software to undertake plate reading is preferred. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Multicenter clinical evaluation of VRESelect agar for identification of vancomycin-resistant Enterococcus faecalis and Enterococcus faecium.

    Science.gov (United States)

    Anderson, Neil W; Buchan, Blake W; Young, Carol L; Newton, Duane W; Brenke, Connie; Lapsley, Linda; Granato, Paul A; Ledeboer, Nathan A

    2013-08-01

    A chromogenic medium for identification of vancomycin-resistant Enterococcus faecalis and Enterococcus faecium, VRESelect, was compared to bile esculin azide agar with 6 μg/ml vancomycin (BEAV) for the isolation of vancomycin-resistant enterococci (VRE) from stool specimens. At 24 to 28 h, VRESelect demonstrated 98.7% (confidence interval [CI], 96.1 to 99.7%) sensitivity and 99.0% (CI, 98.0 to 99.6%) specificity versus 85.1% (CI, 79.8 to 89.5%) and 90.1% (CI, 79.8 to 89.5%) sensitivity and specificity, respectively, for BEAV.

  3. Enumerating actinomycetes in compost bioaerosols at source—Use of soil compost agar to address plate 'masking'

    Science.gov (United States)

    Taha, M. P. M.; Drew, G. H.; Tamer Vestlund, A.; Aldred, D.; Longhurst, P. J.; Pollard, S. J. T.

    Actinomycetes are the dominant bacteria isolated from bioaerosols sampled at composting facilities. Here, a novel method for the isolation of actinomycetes is reported, overcoming masking of conventional agar plates, as well as reducing analysis time and costs. Repeatable and reliable actinomycetes growth was best achieved using a soil compost media at an incubation temperature of 44 °C and 7 days' incubation. The results are of particular value to waste management operators and their advisors undertaking regulatory risk assessments that support environmental approvals for compost facilities.

  4. High internal phase agar hydrogel dispersions in cocoa butter and chocolate as a route towards reducing fat content.

    Science.gov (United States)

    Skelhon, Thomas S; Olsson, Patrik K A; Morgan, Adam R; Bon, Stefan A F

    2013-09-01

    Reducing the fat content of chocolate formulations is a major challenge for the confectionery industry. We report the suspension of aqueous microgel agar particles of up to 80% v/v within sunflower oil, cocoa butter, and ultimately chocolate. The optimised emulsification process involves a shear-cooling step. We demonstrate the versatility of our method when applied to white, milk, and dark chocolate formulations, whilst preserving the desired polymorph V of the cocoa butter matrix. In addition, we show that this technology can be used as a strategy to disperse alcoholic beverages into chocolate confectionery.

  5. Enumeration of coagulase and thermonuclease-positive Staphylococcus spp. in raw milk and fresh soft cheese: an evaluation of Baird-Parker agar, Rabbit Plasma Fibrinogen agar and the Petrifilm Staph Express count system.

    Science.gov (United States)

    Viçosa, Gabriela Nogueira; Moraes, Paula Mendonça; Yamazi, Anderson Keizo; Nero, Luís Augusto

    2010-06-01

    Staphylococcus spp. are microorganisms that are naturally present in milk and dairy products and are often associated with food-borne diseases outbreaks due to the ability of some strains to produce thermostable enterotoxins. This ability is usually associated with coagulase and thermonuclease production, characteristics that are considered in the microbiological analyses for the control of such microorganisms. The objective of this study was to evaluate the culture media and the methodologies used for the enumeration of coagulase and thermonuclease-positive Staphylococcus spp. in raw milk and fresh soft cheese. Samples of artificially contaminated milk (with coagulase-positive Staphylococcus reference strains) and samples of naturally contaminated raw milk and cheese were submitted for enumeration in Baird-Parker agar (BP), Rabbit Plasma Fibrinogen agar (RPFA) and in the Petrifilm Staph Express count system (STX). No significant differences (P > 0.05) were observed between the mean counts obtained in all of the evaluated culture media. RPFA and STX had good correlation indices between the total and typical colony counts as well as with coagulase and the thermonuclease-positive colony counts. Thus, there is a better association between coagulase and thermonuclease production to typical colony morphology developed on these culture media, leading to more accurate and reliable results than with BP, which demonstrated lower correlation indices between these counts. 2009 Elsevier Ltd. All rights reserved.

  6. Cefixime-tellurite rhamnose MacConkey agar for isolation of Vero cytotoxin-producing Escherichia coli serogroup O26 from Scottish cattle and sheep faeces.

    Science.gov (United States)

    Evans, J; Knight, H I; Smith, A W; Pearce, M C; Hall, M; Foster, G; Low, J C; Gunn, G J

    2008-09-01

    To compare rhamnose MacConkey agar supplemented with cefixime and tellurite (CT-RMac) and tryptone bile X-glucuronide (TBX) agars as isolation media for Vero cytotoxin-producing Escherichia coli (VTEC) serogroup O26 from animal faeces. Nine VTEC O26 were isolated from sheep faeces; out of which six were isolated only on CT-RMac and one was isolated only on TBX. One hundred and twelve VTEC O26 were isolated from calf faeces; out of which 97% were from CT-RMac and 52% were from TBX. In a study of E. coli O26 strains, 84% of VT-positive O26 did not ferment rhamnose when compared with 16% of VT-negative O26. VT-positive (19%) and VT-negative (39%) E. coli O26 strains did not grow on CT-RMac agar. It is important to consider that VTEC O26 strains either may ferment rhamnose or may be sensitive to the CT supplement of CT-RMac agar. This work compares CT-RMac and TBX agars as isolation medium for VTEC O26 from Scottish animal faeces and highlights that VTEC O26 may be missed if only CT-RMac agar is used.

  7. Polysaccharides of algae. Pt. 37. Characterization of hybrid structure of substituted agarose from Polysiphonia morrowii (Rhodophyta, Rhodomelaceae) using. beta. -agarase and /sup 13/C-NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Usov, A.I.; Ivanova, E.G.

    1987-09-01

    Structure of gel-forming galactan from Polysiphonia morrowii was analysed using bacterial ..beta..-agarase and /sup 13/C-nuclear magnetic resonance (/sup 13/C-NMR) spectroscopy. The polysaccharide was shown to contain: a) blocks composed of agarobiose residues, partly 6-O-methylated and 6-sulfated, which are sensitive to enzymolysis; b) extended blocks composed of agarobiose 6-sulfate residues, which are resistant to ..beta..-agarase action. The latter blocks contain also ..beta..-D-galactopyranosyl-(1->4)-..cap alpha..-L-galactopyranose 6.6'-disulfate residues (biogenetic precursors of agarobiose 6-sulfate), which are hardly detectable by /sup 13/C-NMR spectrum of the starting polysaccharide. Action of alkali on the enzyme-resistant fraction afforded a polysaccharide preparation having /sup 13/C-NMR spectrum of agarose 6-sulfate.

  8. The effects of cyclic hydrostatic pressure on chondrogenesis and viability of human adipose- and bone marrow-derived mesenchymal stem cells in three-dimensional agarose constructs.

    Science.gov (United States)

    Puetzer, Jennifer; Williams, John; Gillies, Allison; Bernacki, Susan; Loboa, Elizabeth G

    2013-01-01

    This study investigates the effects of cyclic hydrostatic pressure (CHP) on chondrogenic differentiation of human adipose-derived stem cells (hASCs) in three-dimensional (3-D) agarose constructs maintained in a complete growth medium without soluble chondrogenic inducing factors. hASCs were seeded in 2% agarose hydrogels and exposed to 7.5 MPa CHP for 4 h per day at a frequency of 1 Hz for up to 21 days. On days 0, 7, 14, and 21, the expression levels of collagen II, Sox9, aggrecan, and cartilage oligomeric matrix protein (COMP) were examined by real-time reverse transcriptase-polymerase chain reaction analysis. Gene expression analysis found collagen II mRNA expression in only the CHP-loaded construct at day 14 and at no other time during the study. CHP-loaded hASCs exhibited upregulated mRNA expression of Sox9, aggrecan, and COMP at day 7 relative to unloaded controls, suggesting that CHP initiated chondrogenic differentiation of hASCs in a manner similar to human bone marrow-derived mesenchymal stem cells (hMSC). By day 14, however, loaded hASC constructs exhibited significantly lower mRNA expression of the chondrogenic markers than unloaded controls. Additionally, by day 21, the samples exhibited little measurable mRNA expression at all, suggesting a decreased viability. Histological analysis validated the lack of mRNA expression at day 21 for both the loaded and unloaded control samples with a visible decrease in the cell number and change in morphology. A comparative study with hASCs and hMSCs further examined long-term cell viability in 3-D agarose constructs of both cell types. Decreased cell metabolic activity was observed throughout the 21-day experimental period in both the CHP-loaded and control constructs of both hMSCs and hASCs, suggesting a decrease in cell metabolic activity, alluding to a decrease in cell viability. This suggests that a 2% agarose hydrogel may not optimally support hASC or hMSC viability in a complete growth medium in the

  9. Comparison of the capillary and agarose electrophoresis based multiple locus VNTR (variable number of tandem repeats) analysis (MLVA) on Mycobacterium bovis isolates.

    Science.gov (United States)

    Jenkins, A O; Venter, E H; Hutamo, K; Godfroid, J

    2010-09-28

    Electrophoretic techniques that can be used for genotyping of bacterial pathogens ranges from manual, low-cost, agarose gels to high-throughput capillary electrophoresis sequencing machines. These two methods are currently employed in the electrophoresis of PCR products used in multiple locus VNTR (variable number of tandem repeats) analysis (MLVA), i.e. the agarose electrophoresis (AE) and the capillary electrophoresis (CE). Some authors have suggested that clusters generated by AE are less reliable than those generated by CE and that the latter is a more sensitive technique than the former when typing Mycobacterium tuberculosis complex (MTC) isolates. Because such a claim could have significant consequences for investigators in this field, a comparison was made on 19 Belgian Mycobacterium bovis strains which had previously been genotyped using CE VNTR analysis. The VNTR profiles of the CE VNTR analysis were compared with those obtained by AE VNTR analysis at 14 VNTR loci. Our results indicated that there were no differences in copy numbers at all loci tested when the copy numbers obtained by the AE VNTR analysis were compared with those obtained by CE VNTR analysis. The use of AE VNTR analysis in mycobacterial genotyping does not alter the sensitivity of the MLVA technique compared with the CE VNTR analysis. The AE VNTR can therefore be regarded as a viable alternative in moderately equipped laboratories that cannot afford the expensive equipment required for CE VNTR analysis and data obtained by AE VNTR analysis can be shared between laboratories which use the CE VNTR method. (c) 2010 Elsevier B.V. All rights reserved.

  10. Vibrio algivorus sp. nov., an alginate- and agarose-assimilating bacterium isolated from the gut flora of a turban shell marine snail.

    Science.gov (United States)

    Doi, Hidetaka; Chinen, Akito; Fukuda, Hiroo; Usuda, Yoshihiro

    2016-08-01

    An agarose- and alginate-assimilating, Gram-reaction-negative, non-motile, rod-shaped bacterium, designated strain SA2T, was isolated from the gut of a turban shell sea snail (Turbo cornutus) collected near Noto Peninsula, Ishikawa Prefecture, Japan. The 16S rRNA gene sequence of strain SA2T was 99.59 % identical to that of Vibrio rumoiensis DSM 19141T and 98.19 % identical to that of Vibrio litoralis DSM 17657T. This suggested that strain SA2T could be a subspecies of V. rumoiensis or V. litoralis. However, DNA-DNA hybridization results showed only 37.5 % relatedness to DSM 19141T and 44.7 % relatedness to DSM 17657T, which was far lower than the 70 % widely accepted to define common species. Strain SA2T could assimilate agarose as a sole carbon source, whereas strains DSM 19141T and DSM 17657T could not assimilate it at all. Furthermore, results using API 20NE and API ZYM kits indicated that their enzymic and physiological phenotypes were also different. These results suggested that strain SA2T represented a novel species within the genus Vibrio. The major isoprenoid quinone in SA2T was Q-8, and its major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The major fatty acids were summed feature 3, (comprising C16 : 1ω6c and/or C16 : 1ω7c), C16 : 0, and summed feature 8 (comprising C18 : 1ω6c and/or C18 : 1ω7c). The DNA G+C content of SA2T was 40.7 mol%. The name proposed for this novel species of the genus Vibrio is Vibrio algivorus sp. nov., with the type strain designated SA2T (=DSM 29824T=NBRC 111146T).

  11. Determination of in vitro synergy for dual antimicrobial therapy against resistant Neisseria gonorrhoeae using Etest and agar dilution.

    Science.gov (United States)

    Wind, Carolien M; de Vries, Henry J C; van Dam, Alje P

    2015-03-01

    In response to antimicrobial resistance of Neisseria gonorrhoeae to last-resort extended-spectrum cephalosporins, combination therapy of azithromycin+ceftriaxone is now recommended. Dual therapy can be effective to treat monoresistant strains as well as multidrug-resistant strains, preferably employing the effect of in vitro synergy. As reports on in vitro synergy of azithromycin+ceftriaxone in N. gonorrhoeae are conflicting, in this study an evaluation of this combination was performed using a cross-wise Etest method and agar dilution. Synergy was defined as a fractional inhibitory concentration index (FICI) of ≤0.5. To identify other dual treatment options for gonorrhoea, in vitro synergy was evaluated for 65 dual antimicrobial combinations using Etest. Azithromycin, cefixime, ceftriaxone, colistin, ertapenem, fosfomycin, gentamicin, minocycline, moxifloxacin, rifampicin, spectinomycin and tigecycline were screened for synergy in all possible combinations. No synergy or antagonism was found for any of the 65 combinations. The geometric mean FICI ranged from 0.82 to 2.00. The mean FICI of azithromycin+ceftriaxone was 1.18 (Etest) and 0.55 (agar dilution). The difference between both methods did not result in a difference in interpretation of synergy. Ceftriaxone-resistant strain F89 was tested in all combinations and no synergy was found for any of them. Most importantly, the ceftriaxone minimum inhibitory concentration of F89 was not decreased below the breakpoint with any concentration of azithromycin. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  12. Evaluation of DipStreak containing CNA-MacConkey agar: a new bedside urine culture device.

    Science.gov (United States)

    Colodner, R; Keness, Y

    2000-07-01

    Many bedside urine culture devices have been developed with the aim of reliability, simplicity and use in both the physician's office and the clinical laboratory. To compare a novel bedside urine culture device (DipStreak, Novamed Ltd., Israel) comprising a combination of MacConkey and Columbia CNA blood agar with conventional seeding on the same culture media. A total of 1,000 urine specimens sent to our microbiology laboratory were simultaneously processed by both methods. Results were evaluated after 24 and 48 hours incubation at 37 degrees C. Altogether, 171 (17.1%) and 124 (12.4%) specimens were defined as positive by the conventional method using cutoff values of 10(4) colony-forming units/ml and 10(5) CFU/ml respectively; 178 specimens (17.8%) were defined as contaminated. The sensitivity, specificity, positive and negative predictive values of DipStreak for urinary tract infection were 98.8%, 98.6%, 96% and 99.6% respectively, using a cutoff value of 10(4) CFU/ml, and 99.3%, 99.2%, 96% and 99.8% respectively, using cutoff value of 10(5) CFU/ml. Full agreement between both techniques was 95%. The agreement rate between DipStreak and conventional seeding was remarkably high. These results suggest that DipStreak in the agar combination tested in this study is a useful and precise tool for diagnosing urinary tract infections.

  13. Structural studies of agar-gelatin complex coacervates by small angle neutron scattering, rheology and differential scanning calorimetry.

    Science.gov (United States)

    Singh, S Santinath; Aswal, V K; Bohidar, H B

    2007-08-01

    Agar-gelatin complex coacervates are studied by small angle neutron scattering (SANS), rheology (in both flow and temperature scan modes) and differential scanning calorimetry (DSC) in order to probe the microscopic structure of this dense protein-polysaccharide-rich phase. DSC and isochronal temperature sweep (rheology) experiments yielded a characteristic temperature at approximately 35+/-2 degrees C. Rheology data revealed a second characteristic temperature at approximately 75+/-5 degrees C which was absent in DSC thermograms. In the flow mode, shear viscosity (eta) was found to scale with (Carreau model) applied shear rate (gamma ) as: eta(gamma ) approximately (gamma )(-k) with k=1.2+/-0.2 indicating non-Newtonian and shear-thinning features independent of ionic strength. The static structure factor S(q) deduced from SANS data in the low wave vector (0.018 A(-1)high-q region, called the Ornstein-Zernike regime, S(q) approximately 1/(1+xi(2)q(2)) gave correlation length xi approximately 12+/-2A. The results taken together imply the existence of a weakly interconnected and heterogeneous network structure inside the coacervate phase. Structural features of this material are compared with those of agar and gelatin gel, and gelatin coacervate.

  14. An interlaboratory study on efficient detection of Shiga toxin-producing Escherichia coli O26, O103, O111, O121, O145, and O157 in food using real-time PCR assay and chromogenic agar.

    Science.gov (United States)

    Hara-Kudo, Yukiko; Konishi, Noriko; Ohtsuka, Kayoko; Iwabuchi, Kaori; Kikuchi, Rie; Isobe, Junko; Yamazaki, Takumiko; Suzuki, Fumie; Nagai, Yuhki; Yamada, Hiroko; Tanouchi, Atsuko; Mori, Tetsuya; Nakagawa, Hiroshi; Ueda, Yasufumi; Terajima, Jun

    2016-08-02

    To establish an efficient detection method for Shiga toxin (Stx)-producing Escherichia coli (STEC) O26, O103, O111, O121, O145, and O157 in food, an interlaboratory study using all the serogroups of detection targets was firstly conducted. We employed a series of tests including enrichment, real-time PCR assays, and concentration by immunomagnetic separation, followed by plating onto selective agar media (IMS-plating methods). This study was particularly focused on the efficiencies of real-time PCR assays in detecting stx and O-antigen genes of the six serogroups and of IMS-plating methods onto selective agar media including chromogenic agar. Ground beef and radish sprouts samples were inoculated with the six STEC serogroups either at 4-6CFU/25g (low levels) or at 22-29CFU/25g (high levels). The sensitivity of stx detection in ground beef at both levels of inoculation with all six STEC serogroups was 100%. The sensitivity of stx detection was also 100% in radish sprouts at high levels of inoculation with all six STEC serogroups, and 66.7%-91.7% at low levels of inoculation. The sensitivity of detection of O-antigen genes was 100% in both ground beef and radish sprouts at high inoculation levels, while at low inoculation levels, it was 95.8%-100% in ground beef and 66.7%-91.7% in radish sprouts. The sensitivity of detection with IMS-plating was either the same or lower than those of the real-time PCR assays targeting stx and O-antigen genes. The relationship between the results of IMS-plating methods and Ct values of real-time PCR assays were firstly analyzed in detail. Ct values in most samples that tested negative in the IMS-plating method were higher than the maximum Ct values in samples that tested positive in the IMS-plating method. This study indicates that all six STEC serogroups in food contaminated with more than 29CFU/25g were detected by real-time PCR assays targeting stx and O-antigen genes and IMS-plating onto selective agar media. Therefore, screening

  15. In vitro susceptibility of Bartonella species to 17 antimicrobial compounds: comparison of Etest and agar dilution.

    NARCIS (Netherlands)

    Dorbecker, C.; Sander, A.; Oberle, K.; Schulin-Casonato, T.

    2006-01-01

    OBJECTIVES: In vitro susceptibility testing of 31 Bartonella spp. strains including 21 Bartonella henselae isolates was performed for 17 antimicrobial agents (telithromycin, four macrolides, five fluoroquinolones, five aminoglycosides, doxycycline and rifampicin). METHODS: MICs were determined by

  16. [Analysis of bactericidal material generated by electrical devices advertising bactericidal ability against bacteria on the agar gel plates].

    Science.gov (United States)

    Nishimura, Hidekazu

    2012-11-01

    Several Japanese companies sell electrical devices advertised as effective in inactivating viruses and killing bacteria by releasing special materials, e.g., Plasmacluster ions, Nanoe particle and minus ions, into the air. These companies claim that their devices killed bacteria on plates in their own experiments. We tested device effectiveness using the same experiments from the Plasmacluster ioniser SHARP Co., Japan, the Nanoe generator Panasonic Co., Japan, and the Vion KING JIM Co., Japan, to test their advertising claims. Bactericidal ability on agar plate was tested, using Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus cereus, and Enterococcus faecalis as follows: the medium containing a certain amount of each bacterium was put onto an agar plate and smeared. Plates were kept in a closed chamber (inner volume 14.4 m3) or a glove box (inner volume 0.2 m), with one of the devices run for 2 hours. Plates not exposed to any device were used as controls. Each plate was retrieved and put in an incubator to count the number of bacterial colonies formed on the plate. There was no significant difference in the number of colonies on plates exposed to devices compared to control, in the number for all devices, or in all bacteria tested in experiments in the 14.4 m3 chamber. These results strongly suggest that these devices have almost no bactericidal effect, at least in space exceeding this volume. Colony formation was suppressed in the glove box in all devices and in all bacteria tested except P. aeruginosa, although the degree of suppression differed among experiments. The colony formation suppression mechanism was analyzed, and indicated that:colony formation did not change even after the removal of Plasmacluster ions, Nanoe particles, or negative ions from the air, while colony formation was decreased drastically by the removal of ozone from space, which was revealed to be generated inevitably during device operation. These results strongly suggest that the

  17. Inactivation of pathogenic bacteria inoculated onto a Bacto™ agar model surface using TiO2-UVC photocatalysis, UVC and chlorine treatments.

    Science.gov (United States)

    Yoo, S; Ghafoor, K; Kim, S; Sun, Y W; Kim, J U; Yang, K; Lee, D-U; Shahbaz, H M; Park, J

    2015-09-01

    The aim of this study was to study inactivation of different pathogenic bacteria on agar model surface using TiO2-UV photocatalysis (TUVP). A unified food surface model was simulated using Bacto(™) agar, a routinely used microbial medium. The foodborne pathogenic bacteria Escherichia coli K12 (as a surrogate for E. coli O157:H7), Salmonella Typhimurium, Staphylococcus aureus and Listeria monocytogenes were inoculated onto the agar surface, followed by investigation of TUVP-assisted inactivation and morphological changes in bacterial cells. The TUVP process showed higher bacterial inactivation, particularly for Gram-negative bacteria, than UVC alone and a control (dark reaction). A TUVP treatment of 17·2 mW cm(-2) (30% lower than the UVC light intensity) reduced the microbial load on the agar surface by 4·5-6·0 log CFU cm(-2). UVC treatment of 23·7 mW cm(-2) caused 3·0-5·3 log CFU cm(-2) reduction. The use of agar model surface is effective for investigation of bacterial disinfection and TUVP is a promising nonthermal technique. The results showing effects of photocatalysis and other treatments for inactivation of bacterial pathogens on model surface can be useful for applying such processes for disinfection of fruit, vegetables and other similar surfaces. © 2015 The Society for Applied Microbiology.

  18. STUDIES ON THE USE OF AMPICILLIN-DEXTRIN AGAR ASAS AEROMONAS RECOVERY MEDIUM

    Science.gov (United States)

    The Contaminant Candidate List (CCL) includes the unregulated chemical and microbiological contaminants the EPA has identified as possibly posing a significant public risk to consumers if present in drinking water (1). There are three bacterial species listed in the CCL (Aeromon...

  19. Identification of non-mutans streptococci organisms in dental plaques recovering on mitis-salivarius bacitracin agar medium.

    Science.gov (United States)

    Yoo, So Young; Kim, Pyung Sik; Hwang, Ho-Keel; Lim, Seong-Hoon; Kim, Kwang-Won; Choe, Son-Jin; Min, Byung-Moo; Kook, Joong-Ki

    2005-04-01

    The objective of this study was to both isolate and identify non-mutans streptococci organisms (non-MSO) from dental plaques recovered on mitis-salivarius sucrose bacitracin agar (MSB) plates. The dental plaque samples, which had been collected from 63 human subjects, were diluted and plated on MSB. The bacteria growing on the MSB plates were then identified with biochemical tests, as well as with 16S rDNA cloning and sequencing techniques. Our data indicated that bacteria from 30 subjects had been recovered on the MSB plates. Among the 21 typical colonies selected from the 30 subjects, 12 colonies, derived from 10 subjects, were identified as non-MSO. These 12 colonies were determined to be Streptococcus anginosus (8 colonies), S. sanguinis (1 colony), and Pantoea agglomerans (3 colonies). These results strongly suggest that a new selective medium will be required for the reliable isolation of mutans streptococci.

  20. Biomimetic synthesis of hollow calcium carbonate with the existence of the agar matrix and bovine serum albumin

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Jianhua, E-mail: fjh2008@126.com; Wu, Gang; Qing, Chengsong

    2016-01-01

    Proteins play important roles in the process of biomineralization. Vaterite and calcite have been synthesized by the reaction of Na{sub 2}CO{sub 3} and CaCl{sub 2} in the bovine serum albumin (BSA) and agar system. The samples have been characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The shape of CaCO{sub 3} crystal has been analyzed by scanning electronic microscopy (SEM). The results show that calcite is a single product in the absence of BSA, but the product is a mixture of calcite and vaterite in the presence of BSA. The spheral shell of CaCO{sub 3} crystal was obtained when the concentration of BSA increased to 9.0 mg/mL. - Highlights: • Biomimetic synthesis of hollow calcium carbonate • Calcification mechanisms in the presence of both protein and polysaccharides • Biomineralization under the action of protein and polysaccharides.

  1. ImageJ macros for the user-friendly analysis of soft-agar and wound-healing assays.

    Science.gov (United States)

    Nunes, João Paulo Silva; Dias, Adriana Abalen Martins

    2017-04-01

    Recent advances in biological imaging techniques and the enormous amount of data they generate call for the development of computational tools for efficient and reliable high-throughput analysis. Several software applications with this functionality are available, and one of the most commonly used is ImageJ. Here, we present two independent macros (WH_NJ and SA_NJ) for automating and facilitating the analysis of images acquired from two in vitro assays frequently used in cancer studies and drug screening: the wound-healing and soft-agar assays. These two algorithms combine, in a single command, the steps required for the individual analysis of each image using ImageJ. WH_NJ and SA_NJ allow fast, reproducible data analysis without the experimental bias inherent in manual analyses, thus guaranteeing the robustness and reliability of the results.

  2. Black-box modeling to estimate tissue temperature during radiofrequency catheter cardiac ablation: feasibility study on an agar phantom model

    International Nuclear Information System (INIS)

    Blasco-Gimenez, Ramón; Lequerica, Juan L; Herrero, Maria; Hornero, Fernando; Berjano, Enrique J

    2010-01-01

    The aim of this work was to study linear deterministic models to predict tissue temperature during radiofrequency cardiac ablation (RFCA) by measuring magnitudes such as electrode temperature, power and impedance between active and dispersive electrodes. The concept involves autoregressive models with exogenous input (ARX), which is a particular case of the autoregressive moving average model with exogenous input (ARMAX). The values of the mode parameters were determined from a least-squares fit of experimental data. The data were obtained from radiofrequency ablations conducted on agar models with different contact pressure conditions between electrode and agar (0 and 20 g) and different flow rates around the electrode (1, 1.5 and 2 L min −1 ). Half of all the ablations were chosen randomly to be used for identification (i.e. determination of model parameters) and the other half were used for model validation. The results suggest that (1) a linear model can be developed to predict tissue temperature at a depth of 4.5 mm during RF cardiac ablation by using the variables applied power, impedance and electrode temperature; (2) the best model provides a reasonably accurate estimate of tissue temperature with a 60% probability of achieving average errors better than 5 °C; (3) substantial errors (larger than 15 °C) were found only in 6.6% of cases and were associated with abnormal experiments (e.g. those involving the displacement of the ablation electrode) and (4) the impact of measuring impedance on the overall estimate is negligible (around 1 °C)

  3. Effects of extracellular matrix proteins on macrophage differentiation, growth, and function: comparison of liquid and agar culture systems

    Science.gov (United States)

    Armstrong, J. W.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    Both spaceflight and skeletal unloading suppress the haematopoietic differentiation of macrophages (Sonnenfeld et al., Aviat. Space Environ. Med., 61:648-653, 1990; Armstrong et al., J. Appl. Physiol., 75:2734-2739, 1993). The mechanism behind this reduction in haematopoiesis has yet to be elucidated. However, changes in bone marrow extracellular matrix (ECM) may be involved. To further understand the role of ECM products in macrophage differentiation, we have performed experiments evaluating the effects of fibronectin, laminin, collagen type I, and collagen type IV on macrophage development and function. Bone marrow-derived macrophages cultured on four different ECM substrates in liquid culture medium showed less growth than those cultured on plastic. Significant morphological differences were seen on each of the substrates used. Phenotypically and functionally, as measured by class II major histocompatibility molecule (MHCII) expression, MAC-2 expression, and the secretion of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), these macrophages were similar. In contrast, bone marrow-derived macrophages cultured in suspension, using agar, showed no difference in growth when exposed to ECM proteins. However, IL-6 and TNF-alpha secretion was affected by fibronectin, laminin, collagen type I, and collagen type IV in a concentration-dependent manner. We conclude that the ECM products fibronectin, laminin, collagen type I, and collagen type IV have profound effects on macrophage development and function. Additionally, we suggest that an ECM-supplemented agar culture system provides an environment more analogous to in vivo bone marrow than does a traditional liquid culture system.

  4. Improved performance of the modified Hodge test with MacConkey agar for screening carbapenemase-producing Gram-negative bacilli.

    Science.gov (United States)

    Lee, Kyungwon; Kim, Chang Ki; Yong, Dongeun; Jeong, Seok Hoon; Yum, Jong Hwa; Seo, Young Hee; Docquier, Jean-Denis; Chong, Yunsop

    2010-11-01

    The detection of carbapenemases in Gram-negative bacilli is important for optimal patient treatment and to control spread of the resistance. The modified Hodge test can detect carbapenemase-producing Gram-negative bacilli. In this study, we compared the performance of MacConkey agar and Mueller-Hinton agar for metallo-β-lactamase (MBL) and OXA carbapenemase screening. Overall, the performance of Hodge test was better with MacConkey agar due to enhanced release of β-lactamases from the cells in the presence of bile compounds. Concomitant use of the modified Hodge test could resolve most of the problems with uncertain double-disk synergy tests in MBL detection. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. A screening method for β-glucan hydrolase employing Trypan Blue-coupled β-glucan agar plate and β-glucan zymography.

    Science.gov (United States)

    Park, Chang-Su; Yang, Hee-Jong; Kim, Dong-Ho; Kang, Dae-Ook; Kim, Min-Soo; Choi, Nack-Shick

    2012-06-01

    A new screening method for β-(1,3-1,6) glucan hydrolase was developed using a pure β-glucan from Aureobaisidum pullulans by zymography and an LB-agar plate. Paenibacillus sp. was screened as a producer a β-glucan hydrolase on the Trypan Blue-coupled β-glucan LB-agar plate and the activity of the enzyme was analyzed by SDS-β-glucan zymography. The β-glucan was not hydrolyzed by Bacillus spp. strains, which exhibit cellulolytic activity on CMC zymography. The gene, obtaining by shotgun cloning and encoding the β-glucan hydrolase of Paenibacillus sp. was sequenced.

  6. Ethidium bromide modifies the agarose electrophoretic mobility of CAG•CTG alternative DNA structures generated by PCR

    OpenAIRE

    Gomes-Pereira, Mario; Monckton, Darren G.

    2017-01-01

    The abnormal expansion of unstable simple sequence DNA repeats can cause human disease through a variety of mechanisms, including gene loss-of-function, toxic gain-of-function of the encoded protein and toxicity of the repeat-containing RNA transcript. Disease-associated unstable DNA repeats display unusual biophysical properties, including the ability to adopt non-B-DNA structures. CAG?CTG trinucleotide sequences, in particular, have been most extensively studied and they can fold into slipp...

  7. An alternative easy method for antibody purification and analysis of protein-protein interaction using GST fusion proteins immobilized onto glutathione-agarose.

    Science.gov (United States)

    Zalazar, L; Alonso, C A I; De Castro, R E; Cesari, A

    2014-01-01

    Immobilization of small proteins designed to perform protein-protein assays can be a difficult task. Often, the modification of reactive residues necessary for the interaction between the immobilized protein and the matrix compromises the interaction between the protein and its target. In these cases, glutathione-S-transferase (GST) is a valuable tag providing a long arm that makes the bait protein accessible to the mobile flow phase of the chromatography. In the present report, we used a GST fusion version of the 8-kDa protein serine protease inhibitor Kazal-type 3 (SPINK3) as the bait to purify anti-SPINK3 antibodies from a rabbit crude serum. The protocol for immobilization of GST-SPINK3 to glutathione-agarose beads was modified from previously reported protocols by using an alternative bifunctional cross-linker (dithiobis(succinimidyl propionate)) in a very simple procedure and by using simple buffers under physiological conditions. We concluded that the immobilized protein remained bound to the column after elution with low pH, allowing the reuse of the column for alternative uses, such as screening for other protein-protein interactions using SPINK3 as the bait.

  8. Characterization of β-Glucosidase Produced by Aspergillus niger under Solid-State Fermentation and Partially Purified Using MANAE-Agarose

    Science.gov (United States)

    Borges, Diogo G.; Tardioli, Paulo W.; Farinas, Cristiane S.

    2014-01-01

    β-Glucosidase (BGL) is a hydrolytic enzyme with specificity for a wide variety of glycoside substrates, being an enzyme with a large range of biotechnological applications. However, enzyme properties can be different depending both on the microorganism and the cultivation procedure employed. Therefore, in order to explore potential biocatalytical applications of novel enzymes, their characterization is essential. In this work, a BGL synthesized by a selected strain of Aspergillus niger cultivated under solid-state fermentation (SSF) was partially purified and fully characterized in terms of optimum pH, temperature, and thermostability. The single-step purification using MANAE-agarose in a chromatographic column yielded an enzyme solution with specific activity (17.1 IU/mg protein) adequate for the characterization procedures. Electrophoresis SDS-PAGE and size-exclusion chromatography analysis resulted in an estimated molecular mass of 60 kDa. Higher enzyme activities were found in the range between 40 and 65°C and between pH 4 and 5.5, indicating an interesting characteristic for application in the hydrolysis of lignocellulosic biomass for biofuels production. Thermostability studies of purified BGL resulted in half-lives at 37°C of 56.3 h and at 50°C of 5.4 h. These results provide support for further studies of this enzyme towards revealing its potential biotechnological applications. PMID:24940510

  9. Desorption of Lipases Immobilized on Octyl-Agarose Beads and Coated with Ionic Polymers after Thermal Inactivation. Stronger Adsorption of Polymers/Unfolded Protein Composites

    Directory of Open Access Journals (Sweden)

    Jose J. Virgen-Ortíz

    2017-01-01

    Full Text Available Lipases from Candida antarctica (isoform B and Rhizomucor miehei (CALB and RML have been immobilized on octyl-agarose (OC and further coated with polyethylenimine (PEI and dextran sulfate (DS. The enzymes just immobilized on OC supports could be easily released from the support using 2% SDS at pH 7, both intact or after thermal inactivation (in fact, after inactivation most enzyme molecules were already desorbed. The coating with PEI and DS greatly reduced the enzyme release during thermal inactivation and improved enzyme stability. However, using OC-CALB/RML-PEI-DS, the full release of the immobilized enzyme to reuse the support required more drastic conditions: a pH value of 3, a buffer concentration over 2 M, and temperatures above 45 °C. However, even these conditions were not able to fully release the thermally inactivated enzyme molecules from the support, being necessary to increase the buffer concentration to 4 M sodium phosphate and decrease the pH to 2.5. The formation of unfolded protein/polymers composites seems to be responsible for this strong interaction between the octyl and some anionic groups of OC supports. The support could be reused five cycles using these conditions with similar loading capacity of the support and stability of the immobilized enzyme.

  10. Identification of column edges of DNA fragments by using K-means clustering and mean algorithm on lane histograms of DNA agarose gel electrophoresis images

    Science.gov (United States)

    Turan, Muhammed K.; Sehirli, Eftal; Elen, Abdullah; Karas, Ismail R.

    2015-07-01

    Gel electrophoresis (GE) is one of the most used method to separate DNA, RNA, protein molecules according to size, weight and quantity parameters in many areas such as genetics, molecular biology, biochemistry, microbiology. The main way to separate each molecule is to find borders of each molecule fragment. This paper presents a software application that show columns edges of DNA fragments in 3 steps. In the first step the application obtains lane histograms of agarose gel electrophoresis images by doing projection based on x-axis. In the second step, it utilizes k-means clustering algorithm to classify point values of lane histogram such as left side values, right side values and undesired values. In the third step, column edges of DNA fragments is shown by using mean algorithm and mathematical processes to separate DNA fragments from the background in a fully automated way. In addition to this, the application presents locations of DNA fragments and how many DNA fragments exist on images captured by a scientific camera.

  11. Characterization of β-Glucosidase Produced by Aspergillus niger under Solid-State Fermentation and Partially Purified Using MANAE-Agarose

    Directory of Open Access Journals (Sweden)

    Anderson Baraldo Junior

    2014-01-01

    Full Text Available β-Glucosidase (BGL is a hydrolytic enzyme with specificity for a wide variety of glycoside substrates, being an enzyme with a large range of biotechnological applications. However, enzyme properties can be different depending both on the microorganism and the cultivation procedure employed. Therefore, in order to explore potential biocatalytical applications of novel enzymes, their characterization is essential. In this work, a BGL synthesized by a selected strain of Aspergillus niger cultivated under solid-state fermentation (SSF was partially purified and fully characterized in terms of optimum pH, temperature, and thermostability. The single-step purification using MANAE-agarose in a chromatographic column yielded an enzyme solution with specific activity (17.1 IU/mg protein adequate for the characterization procedures. Electrophoresis SDS-PAGE and size-exclusion chromatography analysis resulted in an estimated molecular mass of 60 kDa. Higher enzyme activities were found in the range between 40 and 65°C and between pH 4 and 5.5, indicating an interesting characteristic for application in the hydrolysis of lignocellulosic biomass for biofuels production. Thermostability studies of purified BGL resulted in half-lives at 37°C of 56.3 h and at 50°C of 5.4 h. These results provide support for further studies of this enzyme towards revealing its potential biotechnological applications.

  12. Highly selective and sensitive optical sensor for determination of Pb2+and Hg2+ ions based on the covalent immobilization of dithizone on agarose membrane

    Science.gov (United States)

    Zargoosh, Kiomars; Babadi, Fatemeh Farhadian

    2015-02-01

    A highly sensitive and selective optical membrane for determination of Hg2+ and Pb2+ was prepared by covalent immobilization of dithizone on agarose membrane. In addition to its high stability, reproducibility and relatively long lifetime, the proposed optical sensor revealed good selectivity for target ions over a large number of alkali, alkaline earth, transition, and heavy metal ions. The proposed optical membrane displays linear responses from 1.1 × 10-8 to 2.0 × 10-6 mol L-1 and 1.2 × 10-8 to 2.4 × 10-6 mol L-1 for Hg2+ and Pb2+, respectively. The limits of detection (LOD) were 2.0 × 10-9 mol L-1 and 4.0 × 10-9 mol L-1 for Hg2+ and Pb2, respectively. The prepared optical membrane was successfully applied to the determination of Hg2+ and Pb2+ in industrial wastes, spiked tap water and natural waters without any preconcentration step.

  13. Is there a need to revise the antibiotic concentration in Clinical and Laboratory Standards Institute-Recommended Oxacillin Screen Agar?

    Directory of Open Access Journals (Sweden)

    Niveditha Nagasundaram

    2017-01-01

    Full Text Available Introduction: In routine diagnostic microbiology laboratories, Clinical and Laboratory Standards Institute (CLSI recommends the use of cefoxitin disc, in addition to oxacillin screen agar (OSA of 6 μg/ml for the detection of methicillin-resistant Staphylococcus aureus (MRSA, whereas minimum inhibitory concentration values of oxacillin for S. aureus are ≤2 μg/ml (susceptible and ≥4 μg/ml (resistant. Hence, the study was carried out to evaluate the ability of screen agar with lower concentrations of oxacillin to identify the isolates of MRSA and to compare this with cefoxitin disc diffusion (CDD. Materials and Methods: Six hundred and seventy-six isolates of S. aureus were screened for methicillin resistance by OSA with 2 μg/ml and 4 μg/ml and 6 μg/ml of oxacillin concentration as well as CDD. Polymerase chain reaction for mecA gene was carried out for all isolates which grew on OSA 2, 4 and 6 μg/ml regardless of their cefoxitin susceptibility. Latex agglutination test for penicillin-binding protein 2a was performed for the isolates which grew on OSA 2 and or 4 μg/ml but not on OSA 6 μg/ml. Results: Eight per cent of MRSA isolates was missed by using OSA 6 μg/ml, when compared with other methods. Sensitivities of OSA 2 μg/ml, OSA 6 μg/ml and CDD were found to be 100%, 92.5% and 97.5%, respectively, and specificities for the same were found to be 100%, 100% and 98%, respectively. As per FDA criteria, categorical agreement for OSA 2 μg/ml was found to be 100% in comparison with the reference broth microdilution method. No major and very major discrepancies were documented. Conclusion: Similar findings on a larger and more heterogeneous collection of isolates may indicate the need to revise the concentration of OSA to 2 μg/ml for the detection of MRSA.

  14. Use of agar diffusion assay to measure bactericidal activity of alkaline salts of fatty acids against bacteria associated with poultry processing

    Science.gov (United States)

    The agar diffusion assay was used to examine antibacterial activity of alkaline salts of caproic, caprylic, capric, lauric, and myristic acids. A 0.5M concentration of each fatty acid was dissolved in 1.0 M potassium hydroxide (KOH), and pH of the mixtures was adjusted to 10.5 with citric acid. Solu...

  15. A modified MacConkey agar for selective enumeration of necrotoxigenic E. coli O55 and probiotic E. coli Nissle 1917

    Czech Academy of Sciences Publication Activity Database

    Šplíchalová, Alla; Šplíchal, Igor; Sonnenborn, U.; Rada, V.

    2014-01-01

    Roč. 103, SEP 2014 (2014), s. 82-86 ISSN 0167-7012 R&D Projects: GA ČR GA524/09/0365 Institutional support: RVO:61388971 Keywords : MacConkey agar * E. coil O55 * NTEC Subject RIV: CE - Biochemistry Impact factor: 2.026, year: 2014

  16. Multicentre validation of 4-well azole agar plates as a screening method for detection of clinically relevant azole-resistant Aspergillus fumigatus

    DEFF Research Database (Denmark)

    Arendrup, Maiken Cavling; Verweij, Paul E; Mouton, Johan W

    2017-01-01

    Objectives: Azole-resistant Aspergillus fumigatus is emerging worldwide. Reference susceptibility testing methods are technically demanding and no validated commercial susceptibility tests for moulds currently exist. In this multicentre study a 4-well azole-containing screening agar method was ev...

  17. Two-dimensional network formation of cardiac myocytes in agar microculture chip with 1480 nm infrared laser photo-thermal etching.

    Science.gov (United States)

    Kojima, Kensuke; Moriguchi, Hiroyuki; Hattori, Akihiro; Kaneko, Tomoyuki; Yasuda, Kenji

    2003-11-01

    We have developed a new method that enables agar microstructures to be used to cultivate cells and that allows cell network patterns to be controlled. The method makes use of non-contact three-dimensional photo-thermal etching with a 1480 nm infrared focused laser beam, which is strongly absorbed by water and agar gel, to form the shapes of agar microstructures. It allows microstructures to be easily formed in an agar layer within a few minutes, with cell-culture holes formed by the spot heating of a 100 mW laser and tunnels by the tracing of a 100 microm s(-1), 40 mW laser. We cultivated rat cardiac myocytes in adjacent microstructures and observed synchronized beating in them 90 min after they had made physical contact. Our results indicate that the system can make and use microstructures for cell-network cultivation in a minimal amount of time without any expensive microfabrication facilities or complicated procedures.

  18. Identification of non-streptococcal organisms from human dental plaque grown on the Streptococcus-selective medium mitis-salivarius agar.

    Science.gov (United States)

    Kim, Yeon-Hee; Lee, Si Young

    2015-02-01

    Mitis-salivarius (MS) agar has been used widely in microbial epidemiological studies because oral viridans streptococci can be selectively grown on this medium. Even though the previous findings reported the limited selecting power of MS agar for streptococcus strains, the identities of non-streptococcal strains from human oral samples which can grow on this medium are not clear yet. In this study, we identified non-streptococcal organisms grown on MS agar plates by polymerase chain reaction (PCR) amplification and sequencing of the 16S ribosomal RNA (rRNA) gene. Eighty bacterial colonies on MS plates were isolated from plaque samples, and bacterial identification was achieved with the rapid ID 32 Strep system and mini API reader. The bacterial colonies identified as non-streptococci by the API system were selected for further identification. The 16S rRNA gene was amplified by PCR and verified using DNA sequencing analysis for identification. Sequences were compared with those of reference organisms in the genome database of the National Center for Biotechnology Information using the Basic Local Alignment Search Tool (BLAST). Among the 11 isolated non-streptococcal strains on MS plates, 3 strains were identified as Actinomyces naeslundii, 7 strains were identified as Actinomyces oris and 1 strain were identified as Actinomyces sp. using Blastn. In this study, we showed that some oral Actinomyces species can grow on Streptococcus-selective MS agar plates. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Development of edible films from tapioca starch and agar, enriched with red cabbage (Brassica oleracea) as a sausage deterioration bio-indicator

    Science.gov (United States)

    Aditya Wardana, Ata; Dewanti Widyaningsih, Tri

    2017-12-01

    Sausage spoilage has been identified as a cause of some food poisoning cases. Development of a bioindicator film is one of the alternative methods to detect sausage deterioration. The objectives of this paper were to develop a bioindicator edible films (BEF) from tapioca starch (TS), agar, and red cabbage juice (RC), and to evaluate its performance on sausage deterioration detection. The experiment had a 3x3 randomized factorial experimental design (agar: 3, 5, 7% by weight of TS; RC: 10, 15, 20% v/v based on 100% of suspension). Glycerol was used as the plasticizer. The results showed that the addition of agar into the film solution increased the thickness, elongation, and tensile strength, and decreased water vapour transmission rate (WVTR). While the addition of RC increased the thickness, but decreased elongation, tensile strength, and WVTR. BEF consisting of 2% tapioca starch, 7% (w/w) agar and 10 % (v/v) RC was chosen to apply on sausage. It could detect an increase in the microbial population and in the pH variations as result of sausage deterioration at 24, 48, and 72 h shown through color changes of BEF from bright purple at 0 h to light purple, dark purple-blue, and purple-green color respectively.

  20. Carbapenem disks on MacConkey agar in screening methods for detection of carbapenem-resistant Gram-negative rods in stools.

    Science.gov (United States)

    Blackburn, Julie; Tsimiklis, Catherine; Lavergne, Valéry; Pilotte, Josée; Grenier, Sophie; Gilbert, Andrée; Lefebvre, Brigitte; Domingo, Marc-Christian; Tremblay, Cécile; Bourgault, Anne-Marie

    2013-01-01

    Direct plating of simulated stool specimens on MacConkey agar (MCA) with 10-μg ertapenem, meropenem, and imipenem disks allowed the establishment of optimal zone diameters for the screening of carbapenem-resistant Gram-negative rods (CRGNR) of ≤ 24 mm (ertapenem), ≤ 34 mm (meropenem), and ≤ 32 mm (imipenem).

  1. Carbapenem Disks on MacConkey Agar in Screening Methods for Detection of Carbapenem-Resistant Gram-Negative Rods in Stools

    OpenAIRE

    Blackburn, Julie; Tsimiklis, Catherine; Lavergne, Valéry; Pilotte, Josée; Grenier, Sophie; Gilbert, Andrée; Lefebvre, Brigitte; Domingo, Marc-Christian; Tremblay, Cécile; Bourgault, Anne-Marie

    2013-01-01

    Direct plating of simulated stool specimens on MacConkey agar (MCA) with 10-μg ertapenem, meropenem, and imipenem disks allowed the establishment of optimal zone diameters for the screening of carbapenem-resistant Gram-negative rods (CRGNR) of ≤24 mm (ertapenem), ≤34 mm (meropenem), and ≤32 mm (imipenem).

  2. Comparison of Nostocean hormogonium induction and its motility on solid plates between agar and gellan gum at varying gel matrix concentrations.

    Science.gov (United States)

    Nishizuka, Hiroaki; Hashidoko, Yasuyuki

    2018-03-01

    To establish a sensitive bioassay for Nostocean hormogonium induction, we compared the effectiveness of the morpho-differentiation induction on two gelled plates, agar and gellan gum, for anacardic acid C15:1-Δ 8 decyl ester (1) (100 nmol/disc). On BG-11 0 (nitrogen-free) medium-based 0.6 and 0.8% agar plates, Nostoc sp. strain Yaku-1 isolated from a coralloid root of Cycas revoluta in Yakushima Island showed clear morpho-differentiation from filamentous aggregates into hormogonia, and the induced hormogonia dispersed within 24 h; however, similar hormogonium formation was not observed at agar concentrations of 1.0% or higher. Conversely, hormogonium induction was considerably more pronounced on gellan gum plates than those on agar plates through concentrations ranging from 0.6 to 1.6% even after 12 h of incubation, particularly active on the 0.8-1.0% gellan gum plates. Thus, gellan gum plates can achieve clear results within 12 h and are thus highly useful for primary screening for hormogonium-inducing factors (HIFs).

  3. Experimenting with a Visible Copper-Aluminum Displacement Reaction in Agar Gel and Observing Copper Crystal Growth Patterns to Engage Student Interest and Inquiry

    Science.gov (United States)

    Xu, Xinhua; Wu, Meifen; Wang, Xiaogang; Yang, Yangyiwei; Shi, Xiang; Wang, Guoping

    2016-01-01

    The reaction process of copper-aluminum displacement in agar gel was observed at the microscopic level with a stereomicroscope; pine-like branches of copper crystals growing from aluminum surface into gel at a constant rate were observed. Students were asked to make hypotheses on the pattern formation and design new research approaches to prove…

  4. Screening of tannin acyl hydrolase (E.C.3.1.1.20) producing tannery effluent fungal isolates using simple agar plate and SmF process.

    Science.gov (United States)

    Murugan, K; Saravanababu, S; Arunachalam, M

    2007-03-01

    Industrially important tannase producing fungi were isolated from tannery effluent using simple agar plate method. The isolates were screened by submerged fermentation using auto-controlled bioreactor. The colony diameter on the solid surface media shows high correlation with quantitative production of tannase. The isolate Aspergillus niger shows maximum production of both extracellular and intracellular enzyme.

  5. Novel use of tryptose sulfite cycloserine egg yolk agar for isolation of Clostridium perfringens during an outbreak of necrotizing enterocolitis in a neonatal unit.

    Science.gov (United States)

    Kotsanas, Despina; Carson, Jolene A; Awad, Milena M; Lyras, Dena; Rood, Julian I; Jenkin, Grant A; Stuart, Rhonda L; Korman, Tony M

    2010-11-01

    Clostridium perfringens has been associated with necrotizing enterocolitis (NEC), which is a serious disease of neonates. Our study describes the novel use of selective tryptose sulfite cycloserine with egg yolk agar (TSC-EYA) during a nursery outbreak. This medium provides a rapid, sensitive, and accurate presumptive identification of C. perfringens.

  6. Influence of the environmental factors on the intensity of the oxygen, ammonium, and phosphate metabolism in the agar-containing seaweed Ahnfeltia tobuchiensis (Ahnfeltiales, Rhodophyta)

    Science.gov (United States)

    Cherbadgy, I. I.; Sabitova, L. I.

    2011-02-01

    A complex study of the influence of various environmental factors on the rate of the oxygen (MO 2), ammonium (MNH 4), and phosphate (MPO 4) metabolism in Ahnfeltia tobuchiensis has been carried out in situ in the Izmena Bay of Kunashir Island. The following environmental factors have been included into the investigation: the photosynthetically active radiation (PAR); the ammonium (NH4); the phosphate (PO4); and the tissue content of carbon (C), nitrogen (N), phosphorus (P), and chlorophyll a (Chl). The population of agar-containing seaweed A. tobuchiensis forms a layer with a thickness up to 0.5 m, which occupies about 23.3 km2; the population's biomass is equal to 125000 tons. The quantitative assessment of the organic matter production and nutrient consumption during the oxygen metabolism (MO 2) has been carried out for the whole population. It has been shown that the daily rate depends on the PAR intensity, the seawater concentrations of PO4 and NH4, and the tissue content of N and P ( r 2 = 0.78, p < 0.001). The daily NH4 consumption averages 0.21 μmol/(gDW h) and depends on the NH4 and O2 concentrations in the seawater and on the C and Chl a content in the algal tissues ( r 2 = 0.64, p < 0.001). The daily PO4 consumption averages 0.01 μmol/(gDW h) and depends on the NH4 concentration in the seawater and on the P content in the algal tissues ( r 2 = 0.40, p < 0.001).

  7. Proposal for agar disk diffusion interpretive criteria for susceptibility testing of bovine mastitis pathogens using cefoperazone 30μg disks.

    Science.gov (United States)

    Feßler, Andrea T; Kaspar, Heike; Lindeman, Cynthia J; Peters, Thomas; Watts, Jeffrey L; Schwarz, Stefan

    2017-02-01

    Cefoperazone is a third generation cephalosporin which is commonly used for bovine mastitis therapy. Bacterial pathogens involved in bovine mastitis are frequently tested for their susceptibility to cefoperazone. So far, the cefoperazone susceptibility testing using 30μg disks has been hampered by the lack of quality control (QC) ranges as well as the lack of interpretive criteria. In 2014, QC ranges for 30 μg cefoperazone disks have been established for Staphylococcus aureus ATCC ® 25923 and Escherichia coli ATCC ® 25922. As a next step, interpretive criteria for the susceptibility testing of bovine mastitis pathogens should be developed. For this, 637 bovine mastitis pathogens (including 112 S. aureus, 121 coagulase-negative staphylococci (CoNS), 103 E. coli, 101 Streptococcus agalactiae, 100 Streptococcus dysgalactiae and 100 Streptococcus uberis) were investigated by agar disk diffusion according to the document Vet01-A4 of the Clinical and Laboratory Standards Institute (CLSI) using 30μg cefoperazone disks and the results were compared to the corresponding MIC values as determined by broth microdilution also according to the aforementioned CLSI document. Based on the results obtained and taking into account the achievable milk concentration of cefoperazone after regular dosing, the following interpretive criteria were proposed as a guidance for mastitis diagnostic laboratories: for staphylococci and E. coli ≥23mm (susceptible), 18-22mm (intermediate) and ≤17mm (resistant) and for streptococci ≥18mm (susceptible), and ≤17mm (non-susceptible). These proposed interpretive criteria shall contribute to a harmonization of cefoperazone susceptibility testing of bovine mastitis pathogens. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Scale-up and large-scale production of Tetraselmis sp. CTP4 (Chlorophyta) for CO2 mitigation: from an agar plate to 100-m3 industrial photobioreactors.

    Science.gov (United States)

    Pereira, Hugo; Páramo, Jaime; Silva, Joana; Marques, Ana; Barros, Ana; Maurício, Dinis; Santos, Tamára; Schulze, Peter; Barros, Raúl; Gouveia, Luísa; Barreira, Luísa; Varela, João

    2018-03-23

    Industrial production of novel microalgal isolates is key to improving the current portfolio of available strains that are able to grow in large-scale production systems for different biotechnological applications, including carbon mitigation. In this context, Tetraselmis sp. CTP4 was successfully scaled up from an agar plate to 35- and 100-m 3 industrial scale tubular photobioreactors (PBR). Growth was performed semi-continuously for 60 days in the autumn-winter season (17 th October - 14 th December). Optimisation of tubular PBR operations showed that improved productivities were obtained at a culture velocity of 0.65-1.35 m s -1 and a pH set-point for CO 2 injection of 8.0. Highest volumetric (0.08 ± 0.01 g L -1 d -1 ) and areal (20.3 ± 3.2 g m -2 d -1 ) biomass productivities were attained in the 100-m 3 PBR compared to those of the 35-m 3 PBR (0.05 ± 0.02 g L -1 d -1 and 13.5 ± 4.3 g m -2 d -1 , respectively). Lipid contents were similar in both PBRs (9-10% of ash free dry weight). CO 2 sequestration was followed in the 100-m 3 PBR, revealing a mean CO 2 mitigation efficiency of 65% and a biomass to carbon ratio of 1.80. Tetraselmis sp. CTP4 is thus a robust candidate for industrial-scale production with promising biomass productivities and photosynthetic efficiencies up to 3.5% of total solar irradiance.

  9. Comparison of a direct fecal Shiga-like toxin assay and sorbitol-MacConkey agar culture for laboratory diagnosis of enterohemorrhagic Escherichia coli infection.

    Science.gov (United States)

    Ritchie, M; Partington, S; Jessop, J; Kelly, M T

    1992-02-01

    A direct fecal Shiga-like toxin assay (DSLTA) was used to prospectively screen 9,449 unselected stool samples, received at the British Columbia Provincial Health Laboratories and the Metropolitan Laboratories of Vancouver, for Shiga-like toxin I and Shiga-like toxin II. The results were compared with results of routine stool culture on sorbitol-MacConkey agar (SMAC) for Escherichia coli O157:H7. Of 80 specimens positive by either method, 59 (74%) and 74 (93%) were positive by SMAC and DSLTA, respectively; 53 (66%) were positive by both methods, 21 (26%) were positive by DSLTA only, and 6 (7%) were positive by SMAC only. On further screening, Shiga-like toxin-producing E. coli were detected in 8 (38%) of the 21 stools positive by DSLTA only, including serotypes O157:H7 (1 stool), O26:K60 (5 stools), O128:K67 (1 stool), and O103:H2 (1 stool). For the remaining 13 stools in which no SLTEC was found but DSLTA was positive, clinical information revealed that 11 of 12 patients had diarrheal illnesses, and 4 of these 11 had bloody diarrhea or hemolytic-uremic syndrome. Stools positive only by SMAC were collected earlier in the illness than stools positive by DSLTA, suggesting that free fecal toxin levels may be too low to detect at this time. Overall we found that DSLTA detected 19% more positive specimens than SMAC and that Shiga-like toxin-producing E. coli serotypes other than E. coli O157:H7 are causing disease in the province of British Columbia, Canada.

  10. Evaluation of resistance in a selected field strain of Haemonchus contortus to ivermectin and moxidectin using the Larval Migration on Agar Test

    Directory of Open Access Journals (Sweden)

    Fernanda S. Fortes

    2013-02-01

    Full Text Available Haemonchus contortus is one of the most common and economically significant causes of disease in small ruminants worldwide, and the control programs of parasitic nematodes - including H. contortus - rely mostly on the use of anthelmintic drugs. The consequence of the use of this, as the sole sanitary strategy to avoid parasite infections, was the reduction of the efficacy of all chemotherapeutic products with a heavy selection for resistance. The widespread of anthelmintic resistance and the difficulty of its early diagnosis has been a major concern for the sustainable parasite management on farms. The objective of this research was to determine and compare the ivermectin (IVM and moxidectin (MOX effect in a selected field strain of H. contortus with a known resistance status, using the in vitro larval migration on agar test (LMAT. Third stage larvae of the selected isolate were obtained from faecal cultures of experimentally infected sheep and incubated in eleven increasing diluted concentrations of IVM and MOX (6, 12, 24, 48, 96, 192, 384, 768, 1536, 3072 and 6144µg/mL. The dose-response sigmoidal curves were obtained using the R² value of >0.90 and the lethal concentration (LC50 dose for the tested anthelmintic drugs using a four-parameter logistic model. The LC50 value for MOX was significantly lower than IVM (1.253µg/mL and 91.06µg/mL, identifying the H. contortus isolate as considerably less susceptible to IVM compared to MOX. Furthermore, the LMAT showed a high consistency (p<0.0001 and provided to be a useful diagnostic tool for monitoring the resistance status of IVM and MOX in H. contortus field isolate, as well as it may be used for official routine drug monitoring programs under the Ministry of Agriculture (MAPA guidance.

  11. Mutations in Arabidopsis thaliana genes involved in the tryptophan biosynthesis pathway affect root waving on tilted agar surfaces

    Science.gov (United States)

    Rutherford, R.; Gallois, P.; Masson, P. H.

    1998-01-01

    Arabidopsis thaliana roots grow in a wavy pattern upon a slanted surface. A novel mutation in the anthranilate synthase alpha 1 (ASA1) gene, named trp5-2wvc1, and mutations in the tryptophan synthase alpha and beta 1 genes (trp3-1 and trp2-1, respectively) confer a compressed root wave phenotype on tilted agar surfaces. When trp5-2wvc1 seedlings are grown on media supplemented with anthranilate metabolites, their roots wave like wild type. Genetic and pharmacological experiments argue that the compressed root wave phenotypes of trp5-2wvc1, trp2-1 and trp3-1 seedlings are not due to reduced IAA biosynthetic potential, but rather to a deficiency in L-tryptophan (L-Trp), or in a L-Trp derivative. Although the roots of 7-day-old seedlings possess higher concentrations of free L-Trp than the shoot as a whole, trp5-2wvc1 mutants show no detectable alteration in L-Trp levels in either tissue type, suggesting that a very localized shortage of L-Trp, or of a L-Trp-derived compound, is responsible for the observed phenotype.

  12. Recombinant envelope protein (rgp90) ELISA for equine infectious anemia virus provides comparable results to the agar gel immunodiffusion.

    Science.gov (United States)

    Reis, Jenner K P; Diniz, Rejane S; Haddad, João P A; Ferraz, Isabella B F; Carvalho, Alex F; Kroon, Erna G; Ferreira, Paulo C P; Leite, Rômulo C

    2012-03-01

    Equine infectious anemia (EIA) is an important viral infection affecting horses worldwide. The course of infection is accompanied generally by three characteristic stages: acute, chronic and inapparent. There is no effective EIA vaccine or treatment, and the control of the disease is based currently on identification of EIAV inapparent carriers by laboratory tests. Recombinant envelope protein (rgp90) was expressed in Escherichia coli and evaluated via enzyme-linked immunosorbent assay (ELISA). There was an excellent agreement (95.42%) between the ELISA results using rgp90 and agar gel immunodiffusion test results. AGID is considered the "gold-standard" serologic test for equine infectious anemia (EIA). After 1160 serum samples were tested, the relative sensitivity and specificity of the ELISA were 96.1% and 96.4%, respectively. Moreover, analysis diagnostic accuracy of the ELISA was performed. The ELISA proved robust. Furthermore, good reproducibility was observed for the negative controls and, positive controls for all plates tested. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Correlation between Agar Plate Screening and Solid-State Fermentation for the Prediction of Cellulase Production by Trichoderma Strains

    Directory of Open Access Journals (Sweden)

    Camila Florencio

    2012-01-01

    Full Text Available The viability of converting biomass into biofuels and chemicals still requires further development towards the reduction of the enzyme production costs. Thus, there is a growing demand for the development of efficient procedures for selection of cellulase-producing microorganisms. This work correlates qualitative screening using agar plate assays with quantitative measurements of cellulase production during cultivation under solid-state fermentation (SSF. The initial screening step consisted of observation of the growth of 78 preselected strains of the genus Trichoderma on plates, using microcrystalline cellulose as carbon source. The 49 strains that were able to grow on this substrate were then subjected to a second screening step using the Congo red test. From this test it was possible to select 10 strains that presented the highest enzymatic indices (EI, with values ranging from 1.51 to 1.90. SSF cultivations using sugarcane bagasse and wheat bran as substrates were performed using selected strains. The CG 104NH strain presented the highest EGase activity (25.93 UI·g−1. The EI results obtained in the screening procedure using plates were compared with cellulase production under SSF. A correlation coefficient (R2 of 0.977 was obtained between the Congo red test and SSF, demonstrating that the two methodologies were in good agreement.

  14. Thermal, mechanical, and physical properties of seaweed/sugar palm fibre reinforced thermoplastic sugar palm Starch/Agar hybrid composites.

    Science.gov (United States)

    Jumaidin, Ridhwan; Sapuan, Salit M; Jawaid, Mohammad; Ishak, Mohamad R; Sahari, Japar

    2017-04-01

    The aim of this research is to investigate the effect of sugar palm fibre (SPF) on the mechanical, thermal and physical properties of seaweed/thermoplastic sugar palm starch agar (TPSA) composites. Hybridized seaweed/SPF filler at weight ratio of 25:75, 50:50 and 75:25 were prepared using TPSA as a matrix. Mechanical, thermal and physical properties of hybrid composites were carried out. Obtained results indicated that hybrid composites display improved tensile and flexural properties accompanied with lower impact resistance. The highest tensile (17.74MPa) and flexural strength (31.24MPa) was obtained from hybrid composite with 50:50 ratio of seaweed/SPF. Good fibre-matrix bonding was evident in the scanning electron microscopy (SEM) micrograph of the hybrid composites' tensile fracture. Fourier transform infrared spectroscopy (FT-IR) analysis showed increase in intermolecular hydrogen bonding following the addition of SPF. Thermal stability of hybrid composites was enhanced, indicated by a higher onset degradation temperature (259°C) for 25:75 seaweed/SPF composites than the individual seaweed composites (253°C). Water absorption, thickness swelling, water solubility, and soil burial tests showed higher water and biodegradation resistance of the hybrid composites. Overall, the hybridization of SPF with seaweed/TPSA composites enhances the properties of the biocomposites for short-life application; that is, disposable tray, plate, etc. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Effect of seaweed on mechanical, thermal, and biodegradation properties of thermoplastic sugar palm starch/agar composites.

    Science.gov (United States)

    Jumaidin, Ridhwan; Sapuan, Salit M; Jawaid, Mohammad; Ishak, Mohamad R; Sahari, Japar

    2017-06-01

    The aim of this paper is to investigate the characteristics of thermoplastic sugar palm starch/agar (TPSA) blend containing Eucheuma cottonii seaweed waste as biofiller. The composites were prepared by melt-mixing and hot pressing at 140°C for 10min. The TPSA/seaweed composites were characterized for their mechanical, thermal and biodegradation properties. Incorporation of seaweed from 0 to 40wt.% has significantly improved the tensile, flexural, and impact properties of the TPSA/seaweed composites. Scanning electron micrograph of the tensile fracture showed homogeneous surface with formation of cleavage plane. It is also evident from TGA results that thermal stability of the composites were enhanced with addition of seaweed. After soil burial for 2 and 4 weeks, the biodegradation of the composites was enhanced with addition of seaweed. Overall, the incorporation of seaweed into TPSA enhances the properties of TPSA for short-life product application such as tray, plate, etc. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Evaluation of Tazobactam-Supplemented, Modified Charcoal-Cefoperazone-Deoxycholate Agar for Qualitative Detection of Campylobacter from Chicken Carcass Rinse.

    Science.gov (United States)

    Chon, Jung-Whan; Kim, Young-Ji; Kim, Hong-Seok; Kim, Dong-Hyeon; Jeong, Dong Kwan; Seo, Kun-Ho

    2016-05-01

    Overgrowth of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli on modified charcoal-cefoperazone-deoxycholate agar (mCCDA) is the most common confounding factor for the isolation of Campylobacter from poultry samples. mCCDA modified by supplementation with tazobactam, an ESBL inhibitor, was evaluated for Campylobacter isolation from chicken carcass rinse with regard to isolation rate and selectivity. In total, 120 whole chicken carcasses purchased from retail stores were rinsed with buffered peptone water enriched with 2× blood-free Bolton broth at 42°C for 48 h and then inoculated onto mCCDA with and without tazobactam supplementation (mCCDA or T-mCCDA) at 42°C for 48 h under microaerobic conditions. Suspect colonies were subcultured and confirmed by colony PCR. Plates with tazobactam exhibited a higher Campylobacter isolation rate (56.7% vs. 30.8%, p Campylobacter, p detection of Campylobacter in chicken carcass rinse.

  17. Microanalysis of Organic Pigments in Ancient Textiles by Surface-Enhanced Raman Scattering on Agar Gel Matrices

    Directory of Open Access Journals (Sweden)

    Marilena Ricci

    2016-01-01

    Full Text Available We review some new methods based on surface-enhanced Raman scattering (SERS for the nondestructive/minimally invasive identification of organic colorants in objects whose value or function precludes sampling, such as historic and archeological textiles, paintings, and drawing. We discuss in detail the methodology we developed for the selective extraction and identification of anthraquinones and indigoids in the typical concentration used in textiles by means of an ecocompatible homogeneous nanostructured agar matrix. The extraction system was modulated according to the chemical properties of the target analyte by choosing appropriate reagents for the extraction and optimizing the extraction time. The system has been found to be extremely stable, easy to use and produce, easy to store, and at the same time able to be analyzed even after long time intervals, maintaining its enhancement properties unaltered, without the detriment of the extracted compound. Highly structured SERS band intensities have been obtained from the extracted dyes adopting laser light excitations at 514.5 and 785 nm of a micro-Raman setup. This analytical method has been found to be extremely safe for the analyzed substrates, thus being a promising procedure for the selective analysis and detection of molecules at low concentration in the field of artworks conservation.

  18. Comparison of agar gel immunodiffusion test, enzyme-linked immunosorbent assay and PCR in diagnostics of enzootic bovine leukosis

    Directory of Open Access Journals (Sweden)

    Malovrh Tadej

    2005-01-01

    Full Text Available Bovine leukaemia virus (BLV is a retrovirus that induces a chronic infection in cattle. Once infected, cattle remain virus carriers for life and start to show an antibody response within a few weeks after infection. Eradication and control of the disease are based on early diagnostics and segregation of the carriers. The choice of a diagnostic method depends on the eradication programme, money resources and characteristics of the herd to be analysed. The agar gel immunodiffusion (AGID test has been the serological test of choice for routine diagnosis of serum samples. Nevertheless, in more recent years, the enzyme-linked immunosorbent assay (ELISA has replaced the AGID for large scale testing. For this purpose, commercially available BLV-ELISA kits were compared to the AGID and to the polymerase chain reaction (PCR method performed with two sets of primers, amplifying env region. The ELISA kit based on the p24 core protein was found to be less specific and served as a screening test. The ELISA kit based on the envelope glycoprotein (gpSI served as a verification test and gave a good correlation with the AGID test and PCR method. However, ELISA showed a higher sensitivity than AGID. The p24 based ELiSA was useful for screening a large number of samples, whereas gp51 based ELISA, AGID and PCR were more important for detecting the antibody response against the individual BLV-proteins and therefore for verification of the infection with BLV.

  19. Comparison of Escherichia coli O157:H7 antigen detection in stool and broth cultures to that in sorbitol-MacConkey agar stool cultures.

    Science.gov (United States)

    Stapp, J R; Jelacic, S; Yea, Y L; Klein, E J; Fischer, M; Clausen, C R; Qin, X; Swerdlow, D L; Tarr, P I

    2000-09-01

    We evaluated the Meridian IC-STAT direct fecal and broth culture antigen detection methods with samples from children infected with Escherichia coli O157:H7 and correlated the antigen detection results with the culture results. Stools of 16 children who had recently had stool cultures positive for this pathogen (population A) and 102 children with diarrhea of unknown cause (population B) were tested with the IC-STAT device (direct testing). Fecal broth cultures were also tested with this device (broth testing). The results were correlated to a standard of the combined yield from direct culture of stools on sorbitol-MacConkey (SMAC) agar and culture of broth on SMAC agar. Eleven (69%) of the population A stool specimens yielded E. coli O157:H7 when plated directly on SMAC agar. Two more specimens yielded this pathogen when the broth culture was similarly plated. Of these 13 stool specimens, 8 and 13 were positive by direct and broth testing (respective sensitivities, 62 and 100%). Compared to the sensitivity of a simultaneously performed SMAC agar culture, the sensitivity of direct testing was 73%. Three (3%) of the population B stool specimens contained E. coli O157:H7 on SMAC agar culture; one and three of these stool specimens were positive by direct and broth testing, respectively. The direct and broth IC-STAT tests were 100% specific with samples from children from population B. Direct IC-STAT testing of stools is rapid, easily performed, and specific but is insufficiently sensitive to exclude the possibility of infection with E. coli O157:H7. Performing the IC-STAT test with a broth culture increases its sensitivity. However, attempts to recover E. coli O157:H7 by culture should not be abandoned but, rather, should be increased when the IC-STAT test result is positive.

  20. Application of urea-agarose gel electrophoresis to select non-redundant 16S rRNAs for taxonomic studies: palladium(II) removal bacteria.

    Science.gov (United States)

    Assunção, Ana; Costa, Maria Clara; Carlier, Jorge Dias

    2016-03-01

    The 16S ribosomal RNA (rRNA) gene has been the most commonly used sequence to characterize bacterial communities. The classical approach to obtain gene sequences to study bacterial diversity implies cloning amplicons, selecting clones, and Sanger sequencing cloned fragments. A more recent approach is direct sequencing of millions of genes using massive parallel technologies, allowing a large-scale biodiversity analysis of many samples simultaneously. However, currently, this technique is still expensive when applied to few samples; therefore, the classical approach is still used. Recently, we found a community able to remove 50 mg/L Pd(II). In this work, aiming to identify the bacteria potentially involved in Pd(II) removal, the separation of urea/heat-denatured DNA fragments by urea-agarose gel electrophoresis was applied for the first time to select 16S rRNA-cloned amplicons for taxonomic studies. The major raise in the percentage of bacteria belonging to genus Clostridium sensu stricto from undetected to 21 and 41 %, respectively, for cultures without, with 5 and 50 mg/L Pd(II) accompanying Pd(II) removal point to this taxa as a potential key agent for the bio-recovery of this metal. Despite sulfate-reducing bacteria were not detected, the hypothesis of Pd(II) removal by activity of these bacteria cannot be ruled out because a slight decrease of sulfate concentration of the medium was verified and the formation of PbS precipitates seems to occur. This work also contributes with knowledge about suitable partial 16S rRNA gene regions for taxonomic studies and shows that unidirectional sequencing is enough when Sanger sequencing cloned 16S rRNA genes for taxonomic studies to genus level.

  1. Characterization and evaluation of the novel agarose-nickel composite matrix for possible use in expanded bed adsorption of bio-products.

    Science.gov (United States)

    Rezvani, Azita; Jahanshahi, Mohsen; Najafpour, Ghasem D

    2014-02-28

    Agarose-nickel (Ag-Ni) composite matrix was evaluated for its use in expanded bed adsorption (EBA). Bovine serum albumin (BSA) and lysozyme were used as model proteins in batch and column adsorption studies. Accordingly, Reactive Green 19 (RG19) dye-ligand was covalently immobilized onto the support matrix to prepare affinity adsorbent for protein adsorption. Results were then compared with data obtained from Streamline commercial matrix. In batch experiments RG19 derivatives of Ag-Ni (RG19-Ag-Ni) exhibited high adsorption rate; and also a higher binding capacity of BSA (31.4mg/ml adsorbent) was observed for Ag-Ni compared to the commercial adsorbent. More than 70% of the adsorption capacity was achieved within 30min which is a reasonable contact time for EBA operations. The equilibrium adsorption data well agreed with Langmuir isotherm model. The expanded bed adsorption studies showed a reasonable breakthrough behavior at high flow rates and a higher dynamic binding capacity (DBC) was obtained for novel matrix in compare to streamline at the same fluid velocity. DBC at 10% breakthrough reached 66% of the saturated adsorption capacity at the high flow velocity of 450cm/h which indicates the favorable column efficiency. Additionally, two different Ag-Ni size fractions (75-150 and 150-300μm) were examined to investigate the expanded bed performance dependency on the adsorbent particle size with respect to the hydrodynamic stability and adsorption properties using lysozyme as model protein. Interestingly, the small ones showed less axial dispersion coefficient (adsorption experiments results demonstrated that small size fraction of Ag-Ni matrices acts more effectively for expanded bed adsorption of bio-molecules. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. A novel homocystine-agarose adsorbent for separation and preconcentration of nickel in table salt and baking soda using factorial design optimization of the experimental conditions.

    Science.gov (United States)

    Hashemi, Payman; Rahmani, Zohreh

    2006-02-28

    Homocystine was for the first time, chemically linked to a highly cross-linked agarose support (Novarose) to be employed as a chelating adsorbent for preconcentration and AAS determination of nickel in table salt and baking soda. Nickel is quantitatively adsorbed on a small column packed with 0.25ml of the adsorbent, in a pH range of 5.5-6.5 and simply eluted with 5ml of a 1moll(-1) hydrochloric acid solution. A factorial design was used for optimization of the effects of five different variables on the recovery of nickel. The results indicated that the factors of flow rate and column length, and the interactions between pH and sample volume are significant. In the optimized conditions, the column could tolerate salt concentrations up to 0.5moll(-1) and sample volumes beyond 500ml. Matrix ions of Mg(2+) and Ca(2+), with a concentration of 200mgl(-1), and potentially interfering ions of Cd(2+), Cu(2+), Zn(2+) and Mn(2+), with a concentration of 10mgl(-1), did not have significant effect on the analyte's signal. Preconcentration factors up to 100 and a detection limit of 0.49mugl(-1), corresponding to an enrichment volume of 500ml, were obtained for the determination of the analyte by flame AAS. Application of the method to the determination of natural and spiked nickel in table salt and baking soda solutions resulted in quantitative recoveries. Direct ETAAS determination of nickel in the same samples was not possible because of a high background observed.

  3. The distribution of particles characterized by size and free mobility within polydisperse populations of protein-polysaccharide conjugates, determined from two-dimensional agarose electropherograms.

    Science.gov (United States)

    Tietz, D; Aldroubi, A; Schneerson, R; Unser, M; Chrambach, A

    1991-01-01

    New approaches for the characterization of polydisperse particle populations are presented*. The investigated samples contain virus-sized protein-polysaccharide conjugates which had previously been prepared as immunogens against bacterial meningitis (Hib). The analysis is based on two-dimensional agarose electrophoresis (Serwer-type). This method, like the one of O'Farrell, achieves a separation according to size and charge. It relies on a different principle, however, and is applicable to nondenatured particles which are 100 to more than 1000 times larger in mass than regular uncrosslinked proteins. Data from stained gel patterns are evaluated by the computer program ELPHOFIT, which makes it possible to standardize the gel and to construct a nomogram which defines every position on the gel in terms of particle size and free mobility (related to surface net charge density). The output of ELPHOFIT, consisting of nomogram parameters, is transferred to the image processing program GELFIT. This software is used to evaluate the computer images obtained by digitizing the stained gel patterns: (i) The nomogram is electronically superimposed on the computer image. (ii) The gel pattern is transformed from a curvilinear to a rectangular coordinate system of particle size and free mobility. The center of gravity as well as density maxima are given in coordinates of particle size and free mobility. Ranges of grey levels can be accentuated by adding 16 pseudocolors. (iii) Using surface-stripping techniques, GELFIT provides an estimate for the number of major subpopulations within each preparation. (iv) Numerical values for the distribution of particle size and free mobility are determined. Using program IMAGE, the quantitative physical assessment of a given conjugate preparation is presented in the form of a computer-generated three-dimensional plot, the shape of which serves to identify and characterize the preparation visually. The data analysis based on digitized two

  4. Imaging of VSOP labeled stem cells in agarose phantoms with susceptibility weighted and T2* weighted MR Imaging at 3T: determination of the detection limit.

    Directory of Open Access Journals (Sweden)

    Donald Lobsien

    Full Text Available OBJECTIVES: This study aimed to evaluate the detectability of stem cells labeled with very small iron oxide particles (VSOP at 3T with susceptibility weighted (SWI and T2* weighted imaging as a methodological basis for subsequent examinations in a large animal stroke model (sheep. MATERIALS AND METHODS: We examined ovine mesenchymal stem cells labeled with VSOP in agarose layer phantoms. The experiments were performed in 2 different groups, with quantities of 0-100,000 labeled cells per layer. 15 different SWI- and T2*-weighted sequences and 3 RF coils were used. All measurements were carried out on a clinical 3T MRI. Images of Group A were analyzed by four radiologists blinded for the number of cells, and rated for detectability according to a four-step scale. Images of Group B were subject to a ROI-based analysis of signal intensities. Signal deviations of more than the 0.95 confidence interval in cell containing layers as compared to the mean of the signal intensity of non cell bearing layers were considered significant. RESULTS: GROUP A: 500 or more labeled cells were judged as confidently visible when examined with a SWI-sequence with 0.15 mm slice thickness. Group B: 500 or more labeled cells showed a significant signal reduction in SWI sequences with a slice thickness of 0.25 mm. Slice thickness and cell number per layer had a significant influence on the amount of detected signal reduction. CONCLUSION: 500 VSOP labeled stem cells could be detected with SWI imaging at 3 Tesla using an experimental design suitable for large animal models.

  5. Acoustic Methods to Monitor Protein Crystallization and to Detect Protein Crystals in Suspensions of Agarose and Lipidic Cubic Phase

    Energy Technology Data Exchange (ETDEWEB)

    Ericson, Daniel L.; Yin, Xingyu; Scalia, Alexander; Samara, Yasmin N.; Stearns, Richard; Vlahos, Harry; Ellson, Richard; Sweet, Robert M.; Soares, Alexei S.

    2016-02-01

    Improvements needed for automated crystallography include crystal detection and crystal harvesting. A technique that uses acoustic droplet ejection to harvest crystals was previously reported. Here a method is described for using the same acoustic instrument to detect protein crystals and to monitor crystal growth. Acoustic pulses were used to monitor the progress of crystallization trials and to detect the presence and location of protein crystals. Crystals were detected, and crystallization was monitored in aqueous solutions and in lipidic cubic phase. Using a commercially available acoustic instrument, crystals measuring ~150 µm or larger were readily detected. Simple laboratory techniques were used to increase the sensitivity to 50 µm by suspending the crystals away from the plastic surface of the crystallization plate. This increased the sensitivity by separating the strong signal generated by the plate bottom that can mask the signal from small protein crystals. It is possible to further boost the acoustic reflection from small crystals by reducing the wavelength of the incident sound pulse, but our current instrumentation does not allow this option. In the future, commercially available sound-emitting transducers with a characteristic frequency near 300 MHz should detect and monitor the growth of individual 3 µm crystals.

  6. Acoustic Methods to Monitor Protein Crystallization and to Detect Protein Crystals in Suspensions of Agarose and Lipidic Cubic Phase.

    Science.gov (United States)

    Ericson, Daniel L; Yin, Xingyu; Scalia, Alexander; Samara, Yasmin N; Stearns, Richard; Vlahos, Harry; Ellson, Richard; Sweet, Robert M; Soares, Alexei S

    2016-02-01

    Improvements needed for automated crystallography include crystal detection and crystal harvesting. A technique that uses acoustic droplet ejection to harvest crystals was previously reported. Here a method is described for using the same acoustic instrument to detect protein crystals and to monitor crystal growth. Acoustic pulses were used to monitor the progress of crystallization trials and to detect the presence and location of protein crystals. Crystals were detected, and crystallization was monitored in aqueous solutions and in lipidic cubic phase. Using a commercially available acoustic instrument, crystals measuring ~150 µm or larger were readily detected. Simple laboratory techniques were used to increase the sensitivity to 50 µm by suspending the crystals away from the plastic surface of the crystallization plate. This increased the sensitivity by separating the strong signal generated by the plate bottom that can mask the signal from small protein crystals. It is possible to further boost the acoustic reflection from small crystals by reducing the wavelength of the incident sound pulse, but our current instrumentation does not allow this option. In the future, commercially available sound-emitting transducers with a characteristic frequency near 300 MHz should detect and monitor the growth of individual 3 µm crystals. © 2015 Society for Laboratory Automation and Screening.

  7. The importance of matrix-assisted laser desorption ionization–time of flight mass spectrometry for correct identification of Clostridium difficile isolated from chromID C. difficile chromogenic agar

    Directory of Open Access Journals (Sweden)

    Jonathan H.K. Chen

    2017-10-01

    Full Text Available The clinical workflow of using chromogenic agar and matrix-assisted laser desorption ionization time-of-fight mass spectrometry (MALDI-TOF MS for Clostridium difficile identification was evaluated. The addition of MALDI-TOF MS identification after the chromID C. difficile chromogenic agar culture could significantly improve the diagnostic accuracy of C. difficile.

  8. The effect of reuterin on the lag time of single cells of Listeria innocua grown on a solid agar surface at different pH and NaCl concentrations

    DEFF Research Database (Denmark)

    Rasch, Maria; Metris, A.; Baranyi, J.

    2007-01-01

    The lag time of single cells of Listeria innocua grown on the surface of Brain Heart Infusion Agar was studied by microscopy and image analysis. An experimental set-up that enabled relocation of the cells on the agar surface was developed and used to collect data from 50 to 100 individual cells...

  9. Simple method to determine beta-lactam resistance phenotypes in Pseudomonas aeruginosa using the disc agar diffusion test.

    Science.gov (United States)

    Vedel, G

    2005-10-01

    Pseudomonas aeruginosa is a major opportunistic bacterial pathogen in nosocomial infections because of the increasing prevalence of resistance to many of the commonly used antibiotics. To ensure optimal efficiency of antibiotic treatment against this species, antibiotic susceptibility tests must be interpreted with caution. Most microbiologists now consider it essential to characterize the antibiotic resistance expressed by isolates. Particular resistance mechanisms may be suspected when the bacterium is resistant to several antibiotics in the same family (for example beta-lactam agents). Using the disc agar diffusion test, a simple method was developed to distinguish between the common beta-lactam resistance phenotypes of P. aeruginosa and, consequently, the possible resistance mechanism(s). Over a period of 5 years, we analysed 6300 P. aeruginosa strains isolated from various pathological specimens collected from different wards of Cochin Port-Royal Hospital, and reference and collection strains. Each strain had the wild-type phenotype or an acquired resistance phenotype. Eight anti-pseudomonal beta-lactams (ticarcillin, cefotaxime or moxalactam, cefepime or cefpirome, imipenem, ceftazidime, aztreonam, cefsulodin and ticarcillin + clavulanic acid) were used as phenotypic markers. The following markers were sufficient to distinguish between the wild-type phenotype and the various acquired resistance phenotypes: beta-lactamase synthesis, reduced cell wall permeability and/or increased expression of efflux transporters (active efflux). Detection of resistance phenotypes allows 'interpretive reading' of antibiotic susceptibility tests. Clearly, improved interpretation of antibiotic susceptibility tests is important for a better appreciation of the effect of antimicrobial agents on bacteria such as P. aeruginosa.

  10. Study of chemical interaction induced by ionizing radiation poly(dimethylsiloxane-g-ethylene oxide) in the poly(n-vinyl-2-pyrrolidone) and agar membrane; Estudo da interacao quimica do poli(dimetilsiloxano-g-oxido de etileno) na membrana de poli(n-vinil-2-pirrolidona) e agar induzida com radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Bazzi, Aurea de Souza

    1999-07-01

    Membrane composed by poly(N-vinyl-2-pyrrolidone) (PVP) and agar was formulated with and without poly(dimethylsiloxane-g-ethylene oxide) (SEO) irradiated with electron beam with doses between 10-50 kGy. The radiolytic behaviour of each component, PVP, agar and SEO, was studied when irradiated by gamma ray, in the absence and presence of air and water, by electron paramagnetic resonance (EPR) at 77 K. The chemical interaction of SEO with PVP/agar membrane was investigated by: infrared spectroscopy, energy dispersive X-ray fluorescence, dynamic-mechanical analysis, scanning electron microscopy, gel and swelling analysis. The cytotoxicity of the PVP/agar/SEO membrane was evaluated by cellular suppression. The membrane radicals from PVP ({phi}NC.) and from water (H., OH. and H{sub 2}O) was observed by EPR at 77K. The agar radicals formed by hydrogen abstraction of C{sub 1} and C{sub 3} of {beta}-D-galactose and/or C{sub 1} and C{sub 4} of {alpha}-L-galactose, reacted primarily with water radicals in despite of they also took part in the membrane by chemical bond. The radicals from SEO (.CH{sub 2}{approx}, .Si{approx}, .O{approx}) participated in the inter and intramolecular crosslinking as co-crosslinker by polymeric bridge. The co-crosslinked action depended on its concentration associated to PVP concentration. The presence op acrylates increases the tensile break of the PVP/agar/SEO membrane significantly. (author)

  11. Effect of Nano-ZnO Particle Suspension on Growth of Mung (Vigna radiata and Gram (Cicer arietinum Seedlings Using Plant Agar Method

    Directory of Open Access Journals (Sweden)

    Pramod Mahajan

    2011-01-01

    Full Text Available The present study demonstrates an effect of nano-ZnO particles on the growth of plant seedlings of mung (Vigna radiate and gram (Cicer arietinum. The study was carried out in plant agar media to prevent precipitation of water-insoluble nanoparticles in the test units. Various concentrations of nano-ZnO particles in suspension form were introduced to the agar media, and their effect on the root and shoot growth of the seedlings was examined. The main experimental approach, using correlative light and scanning electron microscopy provided evidence of adsorption of nanoparticles on the root surface. Absorption of nanoparticles by seedlings root was also detected by inductive coupled plasma/atomic emission spectroscopy (ICP-AES. It was found that at certain optimum concentration, the seedlings displayed good growth over control, and beyond that, retardation in growth was observed.

  12. The use of sorbitol-MacConkey agar in conjunction with a specific antiserum for the detection of Vero cytotoxin-producing strains of Escherichia coli O 157.

    Science.gov (United States)

    Kleanthous, H; Fry, N K; Smith, H R; Gross, R J; Rowe, B

    1988-10-01

    Using DNA probes specific for the genes encoding Vero cytotoxins 1 and 2 in hybridization experiments on faecal samples, Vero cytotoxin-producing Escherichia coli (VTEC) of serogroup O 157 were detected in 21 of 63 cases of haemorrhagic colitis, 9 of 31 cases of non-bloody diarrhoea and 14 of 68 cases of haemolytic uraemic syndrome. Compared with these results sorbitol-MacConkey agar in conjunction with a specific O 157 antiserum gave a sensitivity of 62% in haemorrhagic colitis, 56% in non-bloody diarrhoea and 57% in haemolytic uraemic syndrome. The specificity of this method was 100% in all three groups. This demonstrates that sorbitol-MacConkey agar is a useful screening method for the detection of VTEC of serogroup O 157 when used in conjunction with a specific homologous antiserum. However, this method does not detect VTEC belonging to other serogroups and such strains were found, particularly in cases of haemolytic uraemic syndrome.

  13. Historical sources about diseases, death and embalming regarding the family of Jean Antoine Michel Agar, Minister of Finance of Gioacchino Murat.

    Science.gov (United States)

    Marinozzi, S; Gazzaniga, V; Giuffra, V; Fornaciari, G

    2011-06-01

    Among the mummies preserved in the Basilica of San Domenico Maggiore in Naples, there are the bodies of the wife and three children of Jean Antoine Michel Agar, Minister of Finance of Naple's Kingdom during the Monarchy of Joachim Murat (1808-1815). Between 1983 and 1987 paleopathological analyses were performed; in particular, X-ray examination allowed investigation of the health status of the Agar family members and reconstruction of the embalming processes used to preserve the bodies. In addition, an analysis of the historical and archival documents was carried out, to formulate hypotheses about the causes of death, demonstrating how these sources could become important instruments to obtain diagnoses and pathological histories.

  14. Increase in colony-forming efficiency in soft agar of thymus cells from radiation-induced thymomas of NIH Swiss mice

    International Nuclear Information System (INIS)

    Mori, Nobuko; Takamori, Yasuhiko; Hori, Yasuharu

    1982-01-01

    Colony-forming efficiency in soft agar of radiation-induced thymoma in NIH Swiss mice was determined in the presence of cultured medium of reticulo-epitherial cells from normal thymus of NIH Swiss mouse as conditioned medium. A similar experiment was done with thymomas spontaneousely developed in AKR mice. Most of colonies developed in soft agar were not composed of thymic lymphoma cells, but of macrophage-like cells. The ratio of the number of colonies to that of the seeded cells significantly increased in thymomas comparing with that in normal thymus. This result corresponded with the increased number of macrophages in thymoma, as determined by counting phagocytic cells of adherent cells. (author)

  15. Comparison of Two Different Disk Diffusion Agar Tests in Determination of Antibiotic Susceptibility for E-Coli Isolated from Urinary Tract Infection in Pediatrics

    Directory of Open Access Journals (Sweden)

    I. Sedighi

    2010-04-01

    Full Text Available Introduction & Objective: Urinary Tract Infection (UTI is one of the most common infections during childhood and E-Coli is the more predominant pathogen recovered in UTI. Disk Diffusion agar test is a method of choice because it is cost effective, simple, and now routinely used for detection of antibiotic susceptibility. A rapid increase in antibiotic resistance in our region made the authors to design a study to compare this traditional method with two different disk diffusion agar tests.Materials & Methods: Our study was conducted between 2009 and 2010 in Be’sat teaching hospital on 100 pediatric patients ranged 15 days to 13 years old with positive urine culture for E-coli. Antibiogram detection was performed by disk diffusion agar test with two different kits as Padtan-Teb (made in Iran and Mast (made in the U.K. for Co-trimoxazol, Amikacin, Ceftriaxone, Nalidixic Acid, Cefixime, and Nitrofurantoin. At last the data was analyzed by McNemar test.Results: Co-trimoxazol obtained the lowest (23% Padtan-Teb and 26% Mast and Nitrofurantoin had the highest (86% Padtan-Teb and 97% Mast sensitivity in the two methods which were used in our study. The results were statistically significant for Amikacin, Ceftriaxone, Cefixime, and Nitrofurantoin. The data was analyzed by Mc Memar test.Conclusion: According to our study the results of antibiotic susceptibility were more compatible with other non national Disk diffusion agar test and thus we recommend that our manufactures in Iran should increase the quality of their products.

  16. A modified MacConkey agar for selective enumeration of necrotoxigenic E. coli O55 and probiotic E. coli Nissle 1917.

    Science.gov (United States)

    Splichalova, Alla; Splichal, Igor; Sonnenborn, Ulrich; Rada, Vojtech

    2014-09-01

    An agar selective enumeration of necrotoxigenic Escherichia coli O55 (NTEC2) and probiotic E. coli Nissle 1917, using modified MacConkey agar, was developed to study bacterial interference between these E. coli strains in a gnotobiotic piglet model. Replacement of lactose with saccharose in the agar enables the direct visual enumeration of red colonies of E. coli O55 and yellow colonies of E. coli Nissle 1917 that are co-cultured in the same Petri dish. A total of 336 colonies (168 for each color) were subjected to strain-specific PCR identification with LNA probes. Sensitivity, specificity, and positive and negative predictive values were 96.43%, 95.83%, 95.86% and 96.41% respectively in E. coli O55, and 98.21%, 97.02%, 97.06% and 98.19% respectively in E. coli Nissle 1917. Color-based enumeration of both E. coli strains in colonic contents and mesenteric lymph nodes homogenates of gnotobiotic piglets demonstrated the applicability of this method for the gnotobiotic piglet model of enteric diseases. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. An in vitro study of the antimicrobial activity of some endodontic medicaments and their bases using an agar well diffusion assay.

    Science.gov (United States)

    Athanassiadis, B; Abbott, P V; George, N; Walsh, L J

    2009-06-01

    The aim of this study was to determine the in vitro antimicrobial activities of various endodontic medicaments and their bases against selected organisms using an agar diffusion assay. An agar well diffusion assay was used to test the antimicrobial action of some commonly used endodontic medicaments (Ledermix paste, Pulpdent paste, Ultracal paste, and a 50:50 mix of Ledermix and Pulpdent pastes) and their bases. Three bacterial species (E. faecalis, P. micros, P. intermedia) and one yeast (C. albicans) were selected. The diameters of growth inhibition zones and pH were assessed. P. micros demonstrated the highest level of in vitro resistance. Pulpdent and Ultracal pastes had the highest pH (12.64 and 12.53, respectively). The addition of Pulpdent to Ledermix did not increase the zone sizes significantly. All the commercial products showed some in vitro antimicrobial activity. Ledermix paste and the 50:50 Ledermix/Pulpdent mixture being the most effective in this model. The known anti-inflammatory/analgesic properties of Ledermix and the results from this agar model suggest that the 50:50 Ledermix/Pulpdent combination would be the preferred medicament for clinical use in symptomatic cases, even though the addition of calcium hydroxide to Ledermix did not appear to be synergistic in terms of enhancing the antimicrobial action.

  18. Optimization of decolorization process in agar production from Gracilaria lemaneiformis and evaluation of antioxidant activities of the extract rich in natural pigments.

    Science.gov (United States)

    Yuan, Shengliang; Duan, Zhihong; Lu, Yingnian; Ma, Xiaoli; Wang, Sheng

    2018-01-01

    Gracilaria lemaneiformis is mainly used as a raw material source for agar industry, and its extract is rich in natural pigments with antioxidant activities. In this study, a solvent reflux extraction method for decolorization of G. lemaneiformis has been developed in agar production. The extraction conditions were optimized as follows: solvent-to-material ratio, 50:1; ethanol concentration, 70%; number of extractions, 3; extraction time, 0.5 h, under which the total antioxidant yield of the extract reached 2.89 ± 0.88 mg/g dried seaweeds. Their IC 50 values of DPPH radical scavenging activity, hydroxyl radical scavenging activity and superoxide anion scavenging activity were 21.91 ± 1.8 mg/L, 40.59 ± 1.5 mg/L and 160.87 ± 2.8 mg/L, respectively. Further isolation and spectroscopic analysis of natural pigments suggested the strong antioxidant capacities were attributed to chlorophyll derivatives. The results indicate that the decolorization process was able to improve the agar quality, and the extract containing lots of natural pigments had antioxidant activities which may be used in functional food and cosmetics.

  19. Comparison of M.I.C.E. and Etest with CLSI agar dilution for antimicrobial susceptibility testing against oxacillin-resistant Staphylococcus spp.

    Directory of Open Access Journals (Sweden)

    Eloiza H Campana

    Full Text Available OBJECTIVE: The main objective of this study was to comparatively evaluate the performance of M.I.C.E. and Etest methodologies to that of agar dilution for determining the antimicrobial susceptibility profile of oxacillin-resistant Staphylococcus spp. METHODS: A total of 100 oxacillin-resistant Staphylococcus spp. isolates were collected from hospitalized patients at a teaching hospital. Antimicrobial susceptibility testing for vancomycin, teicoplanin and linezolid was performed using the reference CLSI agar dilution method (2009, Etest and M.I.C.E. methodologies. The MIC values were interpreted according to CLSI susceptibility breakpoints and compared by regression analysis. RESULTS: In general, the essential agreement (±1-log2 between M.I.C.E. and CLSI agar dilution was 93.0%, 84.0% and 77.0% for linezolid, teicoplanin and vancomycin, respectively. Essential agreement rates between M.I.C.E. and Etest were excellent (>90.0% for all antibiotics tested. Both strips (M.I.C.E. and Etest yielded two very major errors for linezolid. Unacceptable minor rates were observed for teicoplanin against CoNS and for vancomycin against S. aureus. CONCLUSIONS: According to our results, linezolid and teicoplanin MICs against all staphylococci and S. aureus, respectively, were more accurately predicted by M.I.C.E. strips. However, the Etest showed better performance than M.I.C.E. for predicting vancomycin MICs against all staphylococci. Thus, microbiologists must be aware of the different performance of commercially available gradient strips against staphylococci.

  20. (including travel dates) Proposed itinerary

    Indian Academy of Sciences (India)

    Ashok

    31 July to 22 August 2012 (including travel dates). Proposed itinerary: Arrival in Bangalore on 1 August. 1-5 August: Bangalore, Karnataka. Suggested institutions: Indian Institute of Science, Bangalore. St Johns Medical College & Hospital, Bangalore. Jawaharlal Nehru Centre, Bangalore. 6-8 August: Chennai, TN.