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PubMed1988

Mixed anionic detergent/aliphatic alcohol-polyacrylamide gel electrophoresis alters the separation of proteins relative to conventional sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

The order and relative mobility of proteins on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) is affected by unknown components that are differentially present in SDS preparations obtained from different sources [J.B. Swaney, G.F. Vande Woude, and H.L. Bachrach (1974) Anal. Biochem. 58, 337-346]. The modified separation capabilities of such SDS preparations are useful but the use of this phenomenon in a controlled manner requires that the components responsible for the altered separation be identified. Accordingly, this paper describes a polyacrylamide gel electrophoresis system [mixed alcohol/detergent-polyacrylamide gel electrophoresis (MAD-PAGE)] that employs a mixture of alcohol and detergent instead of SDS alone to modify and enhance protein separation relative to conventional SDS-PAGE. A defined mixture consisting of four sulfated alkyl detergents (dodecyl sulfate, tetradecyl sulfate, hexadecyl sulfate, octadecyl sulfate) as well as the four alcohols of corresponding aliphatic chain length was found to be effective at duplicating the electrophoretic effect of USP-grade SDS and thus changed the relative order and position of polypeptides on electrophoresis relative to conventional SDS-PAGE. This method serves as an adjunct to conventional SDS-PAGE by providing another means of resolving proteins that are not normally resolved by SDS-PAGE. Further, it was found that MAD-PAGE is capable of resolving the NS1 protein of influenza virus into three fractions, whereas conventional SDS-PAGE yields one electrophoretic species. Reelectrophoresis of these novel NS1 bands by conventional SDS-PAGE indicated that they were not modified during MAD-PAGE and probably represented distinct molecular forms present in infected cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcohols↗
PubMed1979

Microheterogeneity of rat, mouse and human alpha1-fetoprotein as revealed by polyacrylamide gel electrophoresis and by crossed immuno-affino-electrophoresis with different lectins.

Polyacrylamide gel electrophoresis and crossed immuno-affino-electrophoresis with several free lectins have been used to characterize and to compare the molecular heterogeneity of rat, mouse and human alpha1-fetoproteins. Each alpha1-fetoprotein contains a variable number of electrophoretic variants depending on the gel porosity. In SDS electrophoresis, two molecular size populations are present in rat alpha1-fetoprotein (Mr = 74 000 and 72 000) and in mouse alpha1-fetoprotein (Mr = 73 000 and 72 000) but only one is observed in human alpha1-fetoprotein (Mr = 70 000). The crossed immuno-affino-electrophoresis patterns square with affinity chromatography results and reveal a marked and characteristic heterogeneity for the three alpha1-fetoprotein species with Concanavalin A, Ricinus communis and Lens culinaris lectins. No lectin-alpha-fetoprotein interaction is apparent with Ulex, Lotus and wheat germ lectins. Since similar patterns are obtained whether with purified alpha1-fetoprotein or with unfractionated fresh fetal sera, it is likely that this heterogeneity is not a consequence of artefactual molecular modifications arising during the purification procedure.

Animals↗
PubMed1996

Genetic relatedness within and between serotypes of Streptococcus pneumoniae from the United Kingdom: analysis of multilocus enzyme electrophoresis, pulsed-field gel electrophoresis, and antimicrobial resistance patterns.

A collection of 54 isolates of invasive Streptococcus pneumoniae of serotypes 3 and 14 and serogroups 6, 9, 19, and 23 was investigated. Multilocus enzyme electrophoresis and pulsed-field gel electrophoresis suggested that two clones were represented in the collection, one of serotype 14 isolates, most of which were resistant to erythromycin, and one of serotype 9V isolates, in which resistance to penicillin (MIC, 1 microgram/ml), cefotaxime, and co-trimoxazole was common. Among other isolates there were only a limited correlation between genetic relatedness measured by multilocus enzyme electrophoresis and expression of the same capsule type. However, isolates with highly related pulsed-field gel electrophoresis patterns always shared the same serotype and highly related allele profiles. Calculation of the index of association suggests a freely recombining population structure with epidemic spread of successful clones.

Child↗
PubMed1984

Two dimensional electrophoresis method for additional characterization of paraproteins in serum. Clinical application of two dimensional electrophoresis, I.

High resolution two dimensional electrophoresis, one of the most potent methods for the analytical separation of proteins, is still used only in specialized laboratories. The present paper describes a two dimensional electrophoresis method, which permits characterization of abnormal serum proteins (paraproteins) and is suitable for application in a clinical laboratory. Both steps of the electrophoresis are performed by the "flat bed technique". The critical transfer from the isoelectric focusing step to the gel of the second dimension is facilitated by use of specially prepared foil stencils. The practicality of the procedure was considerably increased by using commercially available materials such as gels for isoelectric focusing and the silver stain kit. The analysis can be calibrated by measurement of the pH gradient and by using molecular weight protein standards. Moreover, two different samples can be analysed simultaneously in the same gels of the first and the second dimension. This permits a direct comparison of the sample of interest with the sample of reference. Serum samples showing an abnormal band ("M gradient") in routine methods such as agarose gel electrophoresis, were analysed by the described method. Some "M gradients" consisted of single abnormal proteins. Another sample showed a "M gradient" composed of a number of abnormal protein spots in our method. Questions concerning pathobiological and clinical evaluation of the findings justify further studies using this method.

Electrophoresis, Agar Gel↗
PubMed2004

Simultaneous determination of nitrate and nitrite in biological fluids by capillary electrophoresis and preliminary study on their determination by microchip capillary electrophoresis.

In order to develop a highly sensitive and high-throughput screening method for nitrogen monoxide metabolites in biological fluids, we have investigated the simultaneous determination of nitrite and nitrate, using capillary electrophoresis and microchip capillary electrophoresis. In capillary zone electrophoresis, a running buffer based on human serum components with high ionic strength has been developed for the determination of nitrite and nitrate in human serum and human saliva. We obtained successful separation of nitrite and nitrate in the serum and the saliva within 7 min under optimum analytical conditions. Linear calibration curves for nitrite and nitrate for both peak height and area were obtained by a standard addition method. The limits of detection obtained at a signal-to-noise ratio (S/N) of 3 for nitrite and nitrate in the serum were 2.6 and 1.5 microM, respectively. The values of the relative standard deviation of peak height for the serum with 9.2 microM nitrite and 20.9 microM nitrate were 5.7 and 4.1%, respectively. For on-site analysis with high-throughput screening, a microchip capillary electrophoresis method using a microchip made of quartz with a UV detector was developed. In this high-throughput format, using a running buffer with an electroosmotic flow modifier, the peaks of nitrite and nitrate in an artificial serum sample were obtained within 8 s. In high-resolution mode, using the buffer without electroosmotic flow modifier, the separation of nitrite and nitrate was obtained within 15 s. In high-resolution mode, using an artificial serum sample with 50 microM NO2- and 50 microM NO3-, the limits of detection (S/N = 3) of 41 microM for NO2- and 26 microM for NO3- were obtained. The method was applied to human serum and saliva. We obtained peaks due to nitrite and nitrate in 10-fold diluted saliva.

Electrochemistry↗
PubMed1995

Electrophoresis-tutor: an image-based personal computer program that teaches clinical interpretation of protein electrophoresis patterns of serum, urine, and cerebrospinal fluid.

High-resolution protein electrophoresis of serum, urine, and cerebrospinal fluid (CSF) can aid in the diagnosis of multiple myeloma, amyloidosis, macroglobulinemia, multiple sclerosis, and other diseases. Electrophoresis-Tutor is a personal computer program based on approximately 150 digital images that teaches the clinical interpretation of agarose gel electrophoretic patterns. The program is divided into the following sections: introduction, CSF, serum, urine, review of disease states, program navigator, and final exam. The CSF section describes normal and abnormal CSF findings with emphasis on oligoclonal banding, as seen in the CSF of patients with multiple sclerosis. The serum section emphasizes monoclonal gammopathy patterns but also has detailed descriptions of inflammation, liver disease, protein-losing disorders, genetic deficiencies, and other patterns. Monoclonal gammopathy is described in the context of specific associated clinical conditions (e.g., myeloma, amyloidosis). For each monoclonal gammopathy example, results of standard electrophoresis, densitometry, and immunofixation are presented. The review of disease states uses animation to illustrate the development and remission of a variety of pathological patterns. The program navigator allows the user to jump quickly to any place in the program. The optional exam contains 20 questions, and detailed feedback is given after each question. Electrophoresis-Tutor can be used as a stand-alone teaching tool, a companion to traditional instruction, or a reference source.

Blood Proteins↗
PubMed1975

Purification of membrane proteins from Acholeplasma laidlawii by agarose suspension electrophoresis in Tween 20 and polyacrylamide and dextran gel electrophoresis in detergent-free media.

Four of the membrane proteins from Acholeplasma laidlawii that are soluble in the nonionic detergent Tween 20 have been purified by preparative electrophoretic techniques utilizing different supporting media. The last purification step for two of the major proteins was a preparative polyacrylamide gel electrophoresis performed in the absence of any detergent. The proteins were recovered by continuous elution. The purity of the fractions was examined by analytical polyacrylamide gel electrophoresis and crossed immunoelectrophoresis. Two of the minor proteins were purified by dextran gel electrophoresis as the final step, which was also performed in a detergent-free buffer. The separation was followed by scanning the dextran gel in ultraviolet light. The proteins were recovered by slicing the gel and degrading the gel slices with dextranase. The homogeneity of the fractions was checked by electroimmunoassay.

Acholeplasma laidlawii↗
PubMedDate not supplied

Information on DNA conformation derived from transverse pore gradient gel electrophoresis in conjunction with an advanced data analysis applied to capillary electrophoresis in polymer media.

Abnormally slow migration of DNA is conventionally viewed as being due to an abnormal conformation relative to "linear" standards. The evidence for this rests on a few instances where nonlinear DNA structures have been established by independent methods and yield low mobilities relative to standards. Transverse pore gradient gel electrophoresis of authentically bent kinetoplast DNA and of an upstream activator sequence (UAS) of an E. coli operon promoter shows in addition that curves of migration distance vs. gel concentration ("Ferguson curves") of such abnormally conformed DNA differ from those of "linear" standards. Since Ferguson curves are interpretable with regard to molecular size in concordance with a mathematical model (Ogston model), transverse pore gradient gel electrophoresis provides a simple means of correlating abnormally slow migration of DNA with molecular size. In addition, transverse pore gradient gel electrophoresis is able to distinguish between DNA banding which exhibits a steeper dependence on gel concentration than "linear" standards from one which shows the same dependence. The former appears characteristic of circularly bent DNA and gives rise to a substantial retardation, the latter of bending across a knot or kink in the DNA chain associated with a relatively minor retardation relative to standards. Circularly bent restriction fragments formed from kinetoplast DNA retain the characteristic intersecting Ferguson curves on the transverse pore gradient gel. Another authentically "abnormal" DNA structure recognizable on transverse pore gradient gels is supercoiled DNA derived from the reaction of topoisomerase with a plasmid. Different lengths of supercoiled sequences give rise to parallel Ferguson curves clearly intersecting with those of linear standards.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Apolipoprotein (a): a comparison of isoforms identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis or by sodium dodecyl sulfate-agarose gel electrophoresis.

Lipoprotein(a) resembles low density lipoprotein in structure, except that a unique apolipoprotein (apo), apo(a), is linked to apo B-100. Variations in the number of sequence repeats in the apo(a) gene give rise to a range of isoforms. Depending on the method used, 6-30 apo(a) isoforms have been observed; however, the correspondence of these different isoforms has not been reported, making between-study comparisons difficult. In the present study we address this question by characterizing the apo(a) phenotypes of 48 sera using two previously reported separation methods, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE, 3-12% gels) and SDS-agarose gel electrophoresis. In addition, the molecular weight of each isoform was estimated using haptoglobin 2-2 polymers as molecular weight standards. Among the 48 sera, 15 distinct apo(a) isoforms were separated by SDS-PAGE and 28 by SDS-agarose gel electrophoresis. There was excellent correlation between the two nomenclature systems (r = -0.97, p < 0.001, by rank correlation), and the ranges were totally overlapping, with the same two isoforms being identified as the largest and smallest by either method. The apparent molecular mass range for the isoforms was 294-624 kDa, which is in close agreement with the theoretical molecular mass range of 238-643 kDa, calculated from the sequence and carbohydrate content of recombinant apo(a). The disparity in number of isoforms between methods was expected, due to the poorer separation of apo(a) by SDS-PAGE; 3.1 +/- 1.7 (median, 2.0) SDS-agarose isoforms were combined for each SDS-PAGE isoform.(ABSTRACT TRUNCATED AT 250 WORDS)

Apolipoproteins A↗
PubMed1998

Separation and microgram-scale isolation of sea urchin egg granules by electrophoresis in polyvinylpyrrolidone solution, using horizontal gel electrophoresis apparatus with fluorescence detector.

A homogenate of sea urchin (Lytechinus pictus) eggs rich in exocytotic membrane vesicles (granules) was subjected to analytical and preparative electrophoresis in the commercial automated horizontal gel electrophoresis apparatus (HPGE-1000, LabIntelligence, Belmont, CA) capable of intermittent scanning of the migration path, using buffered solutions of polyvinylpyrrolidone (PVP). The nonfluorescent granules were detected by "fluorescence reduction", i.e., a decrease of fluorescence intensity due to the absorbance and/or light scattering properties of the particle. Granules migrated at linear migration rates in buffers ranging from 0 to 2.5% PVP. Two bands were observed and optimally separated in 1.5% PVP solution. As shown by sodium dodecyl sulfate (SDS)-polypeptide patterns, the material recovered from the bands was qualitatively indistinguishable from the two major fractions A and C of granules previously separated by free-flow electrophoresis in the absence of polymer. Ferguson plot analysis failed to provide the sizes of the granules in view of the narrow PVP concentration range available for mobility measurement and the unavailability of chemically homogeneous size standards.

Animals↗
PubMed1998

Isolation and characterization of beta-cyclodextrin sulfates by preparative gradient polyacrylamide gel electrophoresis, capillary electrophoresis and electrospray ionization - mass spectrometry.

A beta-cyclodextrin sulfate mixture has been fractionated using discontinuous gradient polyacrylamide gel electrophoresis. Semidry electrotransfer of the sample onto a positively charged nylon membrane and visualization of a portion of this membrane with Alcian blue stain showed multiple bands. The bands were cut from the remaining portion of the membrane and after washing with 8 M urea, the beta-cyclodextrin sulfate fractions were eluted with 2 M sodium chloride and dialyzed. Analysis of each fraction using high resolution analytical gradient polyacrylamide gel electrophoresis as well as capillary electrophoresis, using indirect detection, showed some of the fractions to be pure while others were mixtures. Each beta-cyclodextrin sulfate fraction was complexed with a basic synthetic peptide and analyzed by electrospray ionization mass spectrometry to define the mass of the components in each mixture and thereby to determine the purity of each sample.

Carbohydrate Sequence↗
PubMed1998

Preparative application of commercial automated gel electrophoresis apparatus to subcellular-sized particles: sequential isolations, fractions re-run, sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, yield and purity.

The analytical and preparative potential of automated gel electrophoresis apparatus with intermittent fluorescence scanning of the migration path, the HPGE-1000 apparatus (LabIntelligence, Belmont, CA) was further developed in application to subcellular-sized particles. Resolution between two rat liver microsome components in agarose (MetaPhor) gel electrophoresis was found to increase with decreasing agarose concentration to 0.04%. It was less, even in an agarose solution at that low concentration, than that in laterally aggregated 4% polyacrylamide gel. The three components of the microsomal preparation were sequentially isolated from 0.6 and 0.8% agarose gel electropherograms. One fraction when re-electrophoresed was found to exhibit the original mobility and did not give rise to the other components. Yields of each component were near-quantitative after one or two electroelution steps. Based on protein content, no impurities could be detected in two of the microsome fractions; the third fraction contained 2% of nonmicrosome impurity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of all three microsome fractions were indistinguishable from one another and from that of the unfractionated microsome preparation.

Animals↗
PubMed2005

Breast cancer protein StarD10 identified by three-dimensional separation using free-flow electrophoresis, reversed-phase high-performance liquid chromatography, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

A 35 kDa protein present in mammary tumors from Neu/ErbB2 transgenic mice was detected on the basis of its cross-reactivity with a phosphoserine-specific antibody against the transcription factor FKHR. To isolate this protein from cytosolic extracts derived from human breast carcinoma cells, we used free-flow electrophoresis in the first dimension to separate proteins according to their charge, followed by reversed-phase high-performance liquid chromatography (RP-HPLC) in the second and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the third dimension. Tryptic digests of Coomassie-stained bands were analyzed by nano-spray ionization-quadrupole quadrupole-time of flight-mass spectrometry identifying StarD10, a START domain containing protein, which cross-reacted with the anti-phospho-FKHR antibody. The site of phosphorylation was identified in immunoaffinity purified Flag-tagged StarD10 from 293T cells transiently expressing this protein. Tryptic phosphopeptides were enriched by immobilized metal affinity chromatography (IMAC) and StarD10 Ser-259-phosphate was identified by tandem mass spectrometry. Thus, free-flow electrophoresis is a powerful high-capacity complementary technique to RP-HPLC and SDS-PAGE for the purification of proteins from complex cell lysates.

Animals↗
PubMed1998

Mutation analyses of KRAS exon 1 comparing three different techniques: temporal temperature gradient electrophoresis, constant denaturant capillary electrophoresis and allele specific polymerase chain reaction.

Mutations in the KRAS gene is a key event in the carcinogenesis of many human cancers and may serve as a diagnostic marker and a target for therapeutic intervention. In this study we have applied three different techniques for mutation detection of KRAS exon 1 mutations: Allele specific polymerase chain reaction (AS-PCR), temporal temperature gradient electrophoresis (TTGE) and constant denaturant capillary electrophoresis (CDCE). Samples from 191 sporadic colon carcinomas were analyzed. AS-PCR were performed with oligonucleotides specific for know mutations in codon 12 and 13 of the KRAS gene. In TTGE analyses, linear ramping of the temperature were performed during electrophoresis in a constant denaturant gel. CDCE analyses were performed using fluorescin labeled PCR-products. Separation was achieved under constant denaturing conditions using high temperature in a gel-filled capillary followed by laser detection. A mutated KRAS gene was found in 42/191 (22.0%) of the samples using AS-PCR, in 62/191 (32.5%) using TTGE and in 66/191 (34.6%) of the samples using CDCE. In the TTGE and CDCE analyses the sequence of the mutant were determined by comparing the electrophoretic pattern to that of known mutations or by mixing the sample with known mutations prior to reanalysis. In a titration experiment mixing mutant and wild-type alleles prior to PCR, the sensitivity for mutation detection was shown to be 10(-2) for TTGE and under optimized conditions 10(-3) for CDCE.

Alleles↗
PubMed1999

Characterization of nosocomial Serratia marcescens isolates: comparison of Fourier-transform infrared spectroscopy with pulsed-field gel electrophoresis of genomic DNA fragments and multilocus enzyme electrophoresis.

A total of 66 Serratia marcescens isolates from 46 patients was investigated by macrorestriction using XbaI followed by pulsed-field gel electrophoresis. 7 restriction fragment patterns attributable to more than one patient and 9 individual patterns were identified. The isolates were additionally characterized by multilocus enzyme electrophoresis and Fourier-transform infrared spectroscopy. The macrorestriction patterns and the multilocus enzyme electrophoresis patterns corresponded fairly well while the classifications derived from these methods were not completely congruent. The grouping achieved by Fourier-transform infrared spectroscopy on the basis of high (> 1000) and moderately high heterogeneity values (300) was consistent with the macrorestriction results. Grouping on a lower heterogeneity level did not contribute to further discrimination. In general, Fourier-transform infrared spectroscopy was less discriminatory than the two other methods, but easier to perform. Therefore, laboratories equipped with the necessary devices may use it to rapidly select bacterial isolates for macrorestriction or other well established characterization procedures.

Cross Infection↗
PubMed1996

Two-dimensional separations: capillary electrophoresis coupled to channel gel electrophoresis.

Two-dimensional separations provide extremely high peak capacities. Coupling capillary zone electrophoresis with ultrathin channel gel electrophoresis offers a convenient and efficient way to perform such two-dimensional microseparations. By means of in situ polymerization, high-concentration (up to 50%T) polyacrylamide gels are prepared in 75 mm long, 25 mm wide, and 40 microns thick rectangular channels. By moving the outlet end of the capillary electrophoresis capillary across the entrance of the channel, both separations are completely preserved. Mixtures of peptides labeled by fluorescein isothiocyanate (FITC) are well resolved in less than 15 min, with theoretical plate numbers in the range of 20,000-50,000 for each independent separation. Significant enhancement in separation efficiency and peak capacity over one-dimensional separations are demonstrated by this combination. The two-dimensional separations of a model mixture of peptides, a tryptic digest of trypsinogen, and < 0.05% of an individual B2 neuron from the marine mollusk Aplysia californica are presented.

Animals↗
PubMed1993

Typing of group B streptococci: comparison of pulsed-field gel electrophoresis and conventional electrophoresis.

The SmaI restriction endonuclease digestion patterns of chromosomal DNAs from 35 group B streptococci were analyzed by pulsed-field gel electrophoresis (PFGE). Nineteen different patterns and four possible variants were identified. Twenty-four isolates were previously analyzed by conventional electrophoresis of HindIII-digested and/or BglII plus EcoRI double-digested chromosomal DNA. Although interpretations by both methods were essentially the same, PFGE identified as variants two isolates that were previously classified as the same isolate. More importantly, PFGE of the chromosomal DNA of group B streptococci digested with SmaI generated more easily defined patterns, since fewer and better separated bands were obtained, whereas digestion with HindIII or EcoRI plus BglII typically generated 100 or more bands. SalI digestion also yielded easily evaluable results, although the SalI fragments were somewhat smaller than those generated by SmaI. In our hands, PFGE patterns were more easily discerned and interpreted than were patterns previously generated by conventional electrophoresis.

Adult↗