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Search Results: 1 - 10 of 1407 matches for " electrophoresis "
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Optimization of an Alternative Methodology for Simultaneous Analysis of Nitrite and Nitrate in Water from Urban Stream by Capillary Electrophoresis under Direct UV Detection  [PDF]
Marcone Augusto Leal de Oliveira, Denise do Carmo Soares, Gláucia Soares Tostes, Mara do Carmo Guimar?es, Fernando Antonio Simas Vaz
American Journal of Analytical Chemistry (AJAC) , 2012, DOI: 10.4236/ajac.2012.37064
Abstract: An alternative methodology for simultaneous determination of nitrite and nitrate by capillary zone electrophoresis using direct detection UV at 210 nm under reverse electrosmotic flow is proposed. The choice of the electrolyte composition has taken account: the mobility of the anion buffer and of the solutes; the low absorbance of the buffer in 210 nm; high base line stability and analysis time. The electrolyte optimized has consisted of 100 mmol.L–1 TRIS/HCl buffer and 0.15 mmol.L–1 CTAB at pH 8.2. The proposed method was applied successfully in the analysis of nitrite and nitrate in samples from urban stream in the absence of usual sample pretreatment.
Preliminary Comparative Physiological and Biochemical Study of Five Different Goat Breeds Inhabiting Saudi Arabia  [PDF]
Mohammed Salem AL-Harbi, Sayed Amin Mohamed Amer
Natural Resources (NR) , 2012, DOI: 10.4236/nr.2012.34028
Abstract: Three arbitrary chosen enzymes were examined by native-polyacrylamide gel electrophoresis to investigate physiological and genetic variations among five different goat breeds inhabiting Saudi Arabia. The goat breeds were Pakistani, Tihami, Syrian, Masri and Aardi while the investigated enzymes were alkaline phosphatase (ALP), malate dehydrogenase (Mdh) and malic enzyme (ME). Six polymorphic loci with six monomeric alleles have been recorded in all studied breeds. The second locus of ME was characteristic of Syrian breed where it showed dimeric alleles. The similarity matrix that has been calculated according to the number of sharing bands indicated that these breeds have been divided into two groups: Pakistani and Tihami as one group while the other three breeds clustered in another group. The activity of the metabolic enzymes (Mdh and ME) showed concordance with the constructed relationship where the percentage amounts of these enzymes showed significant variations between the two groups more than that occurred within each group. Mdh was expressed in the second group more than in the first while ME showed, nearly, equal expression in the different breeds. Both genetic and physiological results agreed in clustering the studied breeds into Pakistani and Tihami in one group and the other three breeds in another group. This division was based on a few gene loci and a few sampling size and it needs to be supported by collecting more genetic data and more sampling size in a further molecular study.
Determination of Tramadol in Human Serum by Capillary Electrophoresis with the End-Column Electrochemiluminescence Detection  [PDF]
Caiyun Zhang, Tao Liu, Xiaoli Zhang, Erbao Liu
Open Journal of Biophysics (OJBIPHY) , 2013, DOI: 10.4236/ojbiphy.2013.32015

A capillary electrophoresis (CE) coupled with end-column electrochemiluminescence (ECL) detection method for the analysis of tramadol (TMD) has been investigated. ECL detection was working electrode biased at 1.2 V in a 20mmol·L-1 sodium phosphate buffer (pH = 8.0) containing 5 mmol·L-1 Ru \"\"(where bpy = 2,2-bipyridyl). Linear correlation (r 0.997) between ECL intensity and drug concentration was obtained in the range 3 × 10-4 - 6 × 10-6 mol·L-1. The limits of detection (LODs) for tramadol in water was 3.012 × 10-8 mol·L-1(S/N = 3). The relative standard deviation values on peak size (10-5 mol·L-1 level) and migration time for the tramadol were 4.58% and 1.39% (n = 10), respectively. Applicability of the CE-ECL method to the analysis of human serum spiked with tramadol was examined

Determination of Melamine in Quail Egg and Milk with Capillary Zone Electrophoresis  [PDF]
Yu Kong, Chong Wei, Zilong Wang, Zhanwu Hou, Hua Li, Jiang Yu, Jiaqiang Yuan, Yongxi Zhao, Jiangang Long, Yuhai Tang, Meili Gao
American Journal of Analytical Chemistry (AJAC) , 2014, DOI: 10.4236/ajac.2014.54032
Abstract: A capillary zone electrophoresis method was developed for determination of melamine in food samples, such as quail egg and milk products. The CE procedure was performed on fused silica capillary (41 cm × 75 μm I.D.) at 17 kV using pH3.1 60mmol/L phosphate buffer as run buffer and detecting at 200 nm. The proposed method showed good linearity (0.5 - 10.0 μmol/L) and low LOD (0.5 μmol/L) with good reproducibility (RSD% was 2.4 and 3.2 for migration time and peak area respectively), which made it suitable for quantity control of the related food product.
Modifying Polyacrylamide Background Color for the Nitroblue Tetrazolium-Based Superoxide Dismutase Staining Assay  [PDF]
Robert Louis Bertrand, Michael Okechukwu Eze
Advances in Enzyme Research (AER) , 2014, DOI: 10.4236/aer.2014.22008
Abstract: The reduction of nitroblue tetrazolium by superoxide radicals generated from photo-reactive riboflavin has been in use for more than four decades to detect superoxide dismutase (SOD) on nondenaturing polyacrylamide gels. SOD research in medicine and biochemistry has warranted the development of multiple assay variants to overcome specific experimental constraints or to combine the SOD assay with other enzyme assays. Fine-tuning reagent concentrations to effectively visualize bands continue to be a major research obstacle in assay development. Herein we describe a straightforward technique to reliably adjust the background color of polyacrylamide gels without compromising assay efficacy. Low micromolar to low millimolar concentrations of yellow riboflavin can be mixed with the blue of reduced nitroblue tetrazolium to controllably produce blue, purple, yellow-brown, or yellow gel backgrounds. The advantage of this technique is that the assay is not modified by the introduction of new reagents. Quantitative reliability of these alternative stains was assessed by plotting determined band intensity values against known enzyme loads. The correlation (R2) values of trial averages were compared against the average correlation of the standard 0.028 mM riboflavin solution using pooled standard deviation and Student’s T-test at 95% confidence. Assay sensitivity was assessed by comparing lowest possible visible enzyme load of the experimental stains with the 0.028 mM riboflavin standard. No difference in the quantitative reliability was found in any riboflavin concentration. The minimum reliable sensitivity of the assay was found to be 10 ng for each concentration of riboflavin. This technique has already been employed to analyze SOD protein expression levels in extracts of Escherichia coli (Bertrand et al., Med Hypotheses 2012; 78:130-133, 2012; Bertrand & Eze, Adv. Enz. Res., 1: 132-141, 2013).
New Approach for Isolation of Individual Caseins from Cow Milk by the Preparative Electrophoresis  [PDF]
Andrii V. Iukalo
Advances in Biological Chemistry (ABC) , 2014, DOI: 10.4236/abc.2014.46043
Abstract: This paper carried out a comparative analysis of different types of electrophoretic systems which were used for the analysis of casein complex from cow milk (polyacrylamide gel electrophoresis: for the neutral and acidic native conditions, in gradient variant, the presence of sodium dodecyl sulphate or with including urea). Taking into attention the separation efficiency, complexity of electrophoretic system, the impact of system components, we have selected the anode system of the homogeneous gel in the presence of urea as the basis for the preparation of casein fractions. It also changed the composition and the structure of the electrophoretic apparatus. The changes allow purification of casein fractions up to several grams during one stage of treatment (for 5 hours). The purified casein fractions were tested for the homogeneity and have been recommended for using in the biomedical researches, including the processes of the formation of the bioactive peptides.
Molecular Weight Determination of a Protease Extracted from Mucor pusillus: Comparison Methods  [PDF]
Nouani Abdelouahab, Belhamiche Nabila, Slamani Roza, Belbraouet Slimane, Dako Etienne, Audet Pascal, Bellal Mohand Mouloud
Food and Nutrition Sciences (FNS) , 2015, DOI: 10.4236/fns.2015.63035
Abstract: Mucor pepsin, a protease used in milk coagulation, is purified by ion-exchange and by molecular exclusion on Sephadex G100. The molecular weight (MW) is determined by polyacrylamide gel electrophoresis under denaturing conditions in presence of sodium dodecyl sulfate (SDS) and by molecular exclusion chromatography. Approximate evaluation of molecular mass was conducted by elution of known MW proteins (BSA: 67 kDa, pepsin: 35 kDa and trypsin: 23.8 kDa) on Sephadex G-100 under the same conditions as the experimental sample. The electrophoretic profile shows that the active fraction studied appears as a single homogeneous band (monomeric form). According to the curve calibration, the molecular mass of the coagulant fraction is about 48 kDa. For Mucor, the observed MW value seems to be enigmatic. However, this result is confirmed by a proteomic analysis with close MW values obtained using conventional techniques. The protease studied by the Scafold ver. Software 2.0 and the analysis of the protein similarities indicate a MW of 46 kDa and the protease sequence of 427 amino acids.
Enzyme electrophoresis method in analysis of active components of haemostasis system  [PDF]
Ludmila Ostapchenko, Oleksiy Savchuk, Nataliia Burlova-Vasilieva
Advances in Bioscience and Biotechnology (ABB) , 2011, DOI: 10.4236/abb.2011.21004
Abstract: The novel modifications of substrate-containing sodium dodecyl sulfate-polyacrylamide gel electrophoresis that can be used for the detection of proteases and its activators are reported. The protease/activator samples were separated on a protein substrate-SDS-polyacrylamide gel. To detect plasminogen activators fibrinogen and Glu-plasminogen were incorporated into the SDS-PAG followed by 1 h incubation at 37?C in thrombin solution (1 NIH/ml). After electrophoresis the gel was stained according to the standard protocol. To detect fibrin-unspecific plasminogen activators from snake venom incubation in thrombin solution was substituted for 12 h incubation in 50 mM Tris-HCl (pH 7.4). To detect fibrinogen-degrading enzymes fibrinogen-containing gel was used. Activity of protease/activator was visualized in the gel as clear bands against the dark background. These new techniques offer several advantages including determination of the quantity and activity of t-PA and urokinase, however cannot be recommended for precise quantification of activators; the total procedure is quite quick and simple; method is convenient tool for detection of novel protein-protein interactions in haemostasis system; the sensitivity of the method is ≤0.01 IU per track.
Potencial alelopático e identifica??o de compostos secundários em extratos de calopog?nio (Calopogonium mucunoides) utilizando eletroforese capilar
Santos, S.;Moraes, M.L.L;Rezende, M.O.O.;Souza Filho, A.P.S;
Eclética Química , 2011, DOI: 10.1590/S0100-46702011000200003
Abstract: in this paper we describe the assessment of the possible allelopathic potential of organic extracts obtained from leaves of calopogonium mucunoides under laboratory conditions, after that some secondary compounds were identified and quantified using capillary electrophoresis. after the identification and quantification of the compounds, we studied the effects of these compounds on the germination of some common weed, which are actually becoming a real problem in pastures in the state of pará - brazil. calopog?nio presented allelopathic potential. the organic crude extracts obtained from solvents with high dielectric constants (dichloromethane and ethyl acetate) were the most efficient in the inhibition of the weed germination. seeds of mimosa pudica were more affected by the extracts; this fact reveals the specificity of the organic extracts obtained. capillary electrophoresis protocols were highly specific, which makes it possible to identify 5 classes of compounds using the same crude extract samples and analyze them fartly (up to 20min). many of identified compounds show inhibitory effect in the weeds germination, seeds of malicia were the most sensible, the bioassays with the misture of compounds indicated the possibility of synergic effect.
Aplicación de electroforesis capilar para la caracterización de gliadinas de trigos argentinos
Colombo,A.; Ribotta,P.D.; León,A.E.;
Agriscientia , 2008,
Abstract: gliadins are a group of wheat proteins that play a major role in gluten development since they account for net viscosity. despite this fact, gliadins have not been studied as deeply as glutenins because of their unusual solubility properties and their high hydrophobicity. the objectives of this work were to study the gliadin profile of argentinean wheats comprising a broad quality range by means of capillary electrophoresis and to assess the suitability of this technique for wheat cultivar discrimination. for this purpose, chemical compositions of twelve wheat cultivars belonging to different quality groups were determined. besides, flour quality was assessed and wheat gliadins were extracted and analyzed by capillary electrophoresis. the results obtained corroborate the potential of free zone capillary electrophoresis for wheat gliadin separation. additionally, only small amounts of sample are required and sample preparation is simple. moreover, this technique involves straightforward protocols for capillary column cleaning and maintenance. these factors enable many of sample analyses in a relatively short time. suitability of free zone capillary electrophoresis for cultivar discrimination based on gliadin profile was demonstrated, since both qualitative and quantitative differences among protein electrophoresis patterns were found. these distinctions allowed differentiation among several genotypes.
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