bluuebunny/crossref_metadata_2025_split huggingface dataset:
Data treatment in multichannel isotachophoresis
Authors: Schumacher Ernst , Arn Dieter , Thormann Wolfgang 
Published: May 2005

AbstractThis paper describes a microcomputer‐based method for collection and treatment of data from an analytical isotachophoresis apparatus having an array of detectors along the separation trough. The electric field distribution within the separation column is measured as a function of time by means of 256 equidistant detector electrodes. This allows monitoring the detailed approach of the steady isotachophoretic state in a fully automated fashion. Collecting data as well as software for data treatment are discussed together with illustrations.
Immobilized pH gradients for isoelectric focusing: Interaction between histones and histone‐like proteins with the charged polyacrylamide matrix
Authors: Righetti Pier Giorgio , Delpech Marc , Moisand Françoise , Kruh Jacques , Labie Dominique 
Published: May 2005

AbstractIt has been found that polyacrylamide matrices containing immobilized pH gradients interact strongly with at least two classes of proteins, histones and the histone‐like, ‘high‐mobility group’ (HMG) chromatin proteins, forming insoluble complexes. The nature of these interactions has been demonstrated to be purely ionical: the complexes are split by high ionic strength (0.5 M NaCl) and by altering the pH (full disaggregation being obtained at pH 5.5 and at pH 11.5). On the basis of these observations, soluble Immobiline polymers have been made, by polymerizing them in the absence of cross‐linker (N,N′‐methylenebisacrylamide). Several classes of Immobiline polymers can be produced: a) mixed‐type polymers, containing a blend of basic and acidic Immobilines, in such ratios as to obtain any desired pH in solution; b) homopolymers with a pure carboxyl surface; and c) homopolymers with a pure amino surface. These polymers can be synthesized as ‘mono‐pK species’ or as ‘multiple‐pKcoils’, the latter providing a full range of charges over an ample pH‐interval. It has been found that ‘carboxyl’ Immobiline homopolymers preferentially interact with the HMGl component among the HMG class, thus allowing the partial purification from a lysate by a simple precipitation step.
Detection of binding artifacts in gel electrofocusing using a polymeric dye probe
Authors: Cuono Charles B. , Chapo Giselle A. , Chrambach Andreas , Hjelmeland Leonard M. 
Published: May 2005

AbstractPoly R‐480, an amphoteric dye of molecular weight 160 000,is the product of copolymerization reaction and can be expected to yield a polydisperse pattern in polyacrylamide gel isoelectric focusing (PAGIF). Such is indeed obtained in conventional PAGIF using commercial synthetic carrier ampholyte mixtures but not in buffer PAGIF, in which a few discrete dye bands are produced. Upon excision of single bands and segments of zones in buffer PAGIF and PAGIF in SCAMs, respectively, the entire original pattern is reestablished in each case, thereby confirming the artifactual nature of both the simple band pattern as well as the polydisperse patten. The simple pattern in buffer PAGIF prevails in the presence of 8 M urea and 8 mM CHAPS, while the polydisperse pattern obtained in SCAMs is resolved into multiple bands in the presence of either one or both of these agents. These observations suggest: a) hydrophobic and hydrogen bond dye‐dye and/or dye‐SCAM interactions produce the artifactual polydisperse pattern in PAGIF in SCAMs, b) electrostatic dye‐dye interactions are responsible for the artifactual simple band pattern in buffer EF, and c) dye‐SCAM electrostatic interactions produce the artifactual multiple band pattern in the SCAM‐urea‐CHAPS system. These data clearly underline the need for critical experimentation in the evaluation of PAGIF bands and band numbers.
Detection of α‐amylase isoenzymes by means of two‐dimensional electrophoresis followed by blue starch staining
Authors: Kadofuku Tsuyoki , Sato Tsuneo , Manabe Takashi , Okuyama Tsuneo 
Published: May 2005

Abstractα‐Amylase isoenzymes present in human body fluids were separated by two‐dimensional electrophoresis in the absence of denaturing agents and detected by blue starch staining. Human body fluid samples (5 sera, 2 salivas, 1 pancreatic juice and 1 urine) were subjected to the analysis. Two to six activity spots of α‐amylase were detected for each sample. The spots were classified into four main species by their isoelectric points (pI) 6.9, 6.5, 5.8 and 5.3. All the α‐amylase isoenzymes showed apparent molecular weights above 140 000.
Electrophoretic extraction‐concentration of proteins from polyacrylamide gels under alkaline, neutral and acidic conditions
Authors: Hashizume Shuichi , Rashid Mohammad A. , Shoji Masahiro , Kuroda Kazuhiko 
Published: May 2005

AbstractA simple technique has been developed for the electrophoretic extraction of milligram to microgram quantities of protein, under constant monitoring by dye line, in a concentrated form from polyacrylamide gels run under alkaline, neutral and acidic conditions. Typically, the extraction time from 5 gel slices per tube containing about 1.2 mg of bovine serum albumin or α‐chymotrypsinogen A was 3 h, and the maximum concentration of the recovered protein was 5 mg/ml with a total recovery of more than 90% in all cases. Higher protein concentrations (11 mg/ml) could be obtained by increasing the extraction time to 3.5 h or by using resins like glass beads. The alkaline extraction system has been applied to the purification of glutamyl‐tRNA synthetase up to homogeneity, and also to ferritin. This technique can also be used under reducing conditions and the scale of operation can be adjusted by the number of tubes or number of slices.
In vitro [35S]methionine‐labeled protein synthesis in microdissected discrete brain areas: Marked regional differences revealed by two‐dimensional gel electrophoresis
Authors: Gold Mark A. , Heydorn William E. , Creed G. Joseph , Weller Joan L. , Klein David C. , Jacobowitz David M. 
Published: May 2005

AbstractA method is presented for the incorporation of [35S]methionine into proteins from freshly microdissected brain tissue samples. Rats were killed by decapitation, the brain was rapidly removed and sectioned without freezing using a vibratome. Hypothalamic nuclei and circumventricular organs of interest were removed by microdissection and incubated in a media containing [35S]methionine for six hours. Proteins within these tissue samples were then separated by two‐dimensional polyacrylamide gel electrophoresis. The gels were stained with silver, photographed, dried and exposed to autoradiographic film. The results suggest that 1) this technique will prove useful in examining the uptake of radiolabeled amino acids into proteins from discrete nuclei and other brain areas, and 2) there is considerable regional heterogeneity in the uptake of [35S]methionine by proteins from the different brain regions examined in this study.
Forming reproducible density and solute gradients by computer‐controlled cooperation of stepmotor‐driven burettes
Authors: Altland Klaus , Altland Alexander 
Published: May 2005

AbstractA program has been developed for the computer‐controlled cooperation of 4 commercially available stepmotor‐driven burettes to form density gradients in polyacrylamide gels and solute gradients for other purposes such as centrifugation and low pressure chromatography. The slope of the gradients was defined by entering up to 200 endpoints of straight lines with the percentage of the total volume and the concentration of the gradient‐forming solute as coordinates. The possible minimum increment of the discontinuous gradients is 0.5 % of the total range. They are mixed at variable flow rate by two burettes containing the high and low density acrylamide solutions and two additional burettes for the admixture of two catalysts at variable volume proportions. Within 10 min gradients with total volumes between 4 and 650 ml can be delivered. Gradient volumes smaller than 4 ml are possible if an average increment of > 0.5 % is accepted. The program meets the requirements of reproducibility for high resolution gradient gel electrophoresis and isoelectric focusing in immobilized pH gradients. All input data for the definition of the gradients can be displayed as a hard copy by a matrix printer and stored on tape. Thus the device meets the requirements of proper documentation of a given gradient in a publication and for reproduction in another laboratory. Other types of gradients for volumes of up to 1.4 liters can be produced by a subprogram converting the 4 burettes into a gradient pump with continuous outflow as used for column chromatography. The speed is variable between 0.4 ml and 5.2 liters per hour with minor pulsation only in the very low range.
A preliminary evaluation of typing commonly occurring human erythrocyte acid phosphatase (ACP1) phenotypes in bloodstains, using the LKB Immobiline system
Authors: Westwood Sara A. , Sutton John G. 
Published: May 2005

AbstractA preliminary study has been made of the use of immobilised pH gradients (Immobiline gels) for the separation of the six commonly occurring erythrocyte acid phosphatase (ACP1) phenotypes in blood lysates and stains. These pH gradients are immobilised in the matrix of the polyacrylamide gel and possess different properties from conventional isoelectric focusing (IEF) gels. A comparison was made between the profile of the ACP1 isoenzymes apparent on conventional IEF gels with that seen on the Immobiline gels.
Fish species identification by electrophoresis of muscle proteins in sodium dodecyl sulfate‐containing polyacrylamide slab gels
Authors: Corzo Javier , Riol‐Cimas José M. , Meléndez‐Hevia Enrique 
Published: May 2005

AbstractFish muscle proteins were separated by slab gel electrophoresis in 10–20 % polyacrylamide gradient gels in presence of sodium dodecyl sulfate. Three muscle extracts were tested: whole homogenate, sarcoplasmic and myofibrillar. Based on differences of the patterns in the 14 000–205 000 molecular weight range, identification of species of different orders, families and genus seems feasible. The most reproducible patterns were obtained with the whole homogenate. No changes were detected in the patterns after cold storage for several days (without freezing).
Measurement of DNA superhelix density by dye titrationslab gel electrophoresis
Authors: Poddar Saibal K. , Maniloff Jack 
Published: May 2005

AbstractAn ethidium bromide titration procedure using electrophoresis in horizontal multigels is described which facilitates measurement of DNA superhelix densities. Using this system, measured superhelix density was found to be dependent on the amount of DNA loaded on the gel.
Easy “home‐made” immobilized pH gradients forisoelectric focusing
Authors: Charlionet Roland , Sesboüé Richard , Davrinche Christian 
Published: May 2005

AbstractAcrylic acid, methacrylic acid, itaconic acid and dimethylaminopropylmethacrylamide can easily be introduced in polyacrylamide gels in order to obtain reproducible immobilized pH gradients in the pH range 4–6. These acrylic derivatives are commercially available at a relatively low price.
The influence of mercaptoethanol on the apparent molecular weights of jojoba and standard proteins separated by porosity gradient gel electrophoresis in presence of urea
Authors: Shah Akbar A. 
Published: May 2005

AbstractProteins exhibit higher apparent molecular weights when treated with mercaptoethanol and separated electropretically in a porosity gradient in presence of ureacompared to their apparent molecular weights without mercaptoethanol. This unexpected effect was first noticed with proteins of jojoba. The apparent increase was also seen when oligomers of serum albumin were separated, but was absent with gelatin, indicating a reaction of disulfide groups in the polypeptide chain of serum albumin. When the proteins were treated with hydrogen peroxide prior to electrophoresis the apparent increase of molecular weights of jojoba proteins after mercaptoethanol treatment was less evident in the presence of monomethylurea and was absent in gels containing tetramethylurea.
Rapid detection and characterization of plant virused by agarose gel electrophoresis: Size, surface charge and heterogeneity of panicum mosaic and related viruses
Authors: Serwer Philip , Moreno Elena T. , Hayes Shirley J. , Berger Philip , Langham Marie , Toler Robert W. 
Published: May 2005

AbstractUsing panicum mosaic virus (PMV) and several St. Augustine decline strains of PMV (SAD) as test viruses, previously developed procedures of agarose gel electrophoresis (reviewed in P. Serwer, Electrophoresis 1983, 3, 375–382) have been used for the first time to detect and characterize plant viruses. PMV and some SAD strains produce two particles that copurify during rate zonal sedimentation, but form separate bands during agarose gel electrophoresis (forms 1 and 2). By measuring electrophoretic mobility (μ) as a function of agarose percentage and correcting for electroosmosis, it was found that: (a) form 1 has a solid support‐free μ (μ0) different from the μ0 of form 2, and (b) forms 1 and 2 have the same radius (14.6 ± 0.6nm). Form 1 is indistinguishable from form 2 by either electron microscopy or sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. The μ0 of form 1 and the relative amount of forms 1 and 2 vary with the virus strain and can be used to help identify strains. A previously described satellite of PMV and some SAD strains also has two forms. The radius of the satellite of one SAD strain was found to be 7.6 ± 0.3 nm. A procedure of differential gel staining was developed for distinguishing the 14.6 nm virus from its 7.6 nm satellite. After agarose gel electrophoresis of either totally unfractionated or partially fractionated, infected grass extracts, virus particles wer detected without interference from host components. The procedures used here should be useful for rapid disease diagnosis and strain typing of the above and possibly other plant viruses.
Glycosylation of human abumin in diabetes mellitus: Extensive microheterogeneity of serum and urinary species as revealed by isoelectric focusing
Authors: Candiano Giovanni , Ghiggeri Gian Marco , Delfino Gerolamo , Queirolo Carlo , Gianazza Elisabetta , Righetti Pier Giorgio 
Published: May 2005

AbstractAlbumin and glycosylated albumin from serum and urine of 10 diabetic patients have been studied by ultrathin‐layer isoelectric focusing andsilver staining. Both total serum albumin and its glycosylated form were microheterogeneous with a main band focused in the pH 4–5 range; in the case of glycosylated ablumin several cathodic bands with pI's up to 7 were found to form a discretely abundant population among the total species. Some similarites and some striking differences were observed for urinary albumin, which, beside the main unmodified albumin with pI ca. 4.8, was enriched in microheteregeneous more anodal bands (PI 4.0–4.7 species). All these anodal bands were tightly bound by concanavalin A‐Sepharose, suggesting their identity as glycosylatedalbumin. these observations indicate that the glycosylation of albumin is not an equimolar reaction, but it can involve many sites of attachement of carbohydrates. The also suggest that albumin species with higher net negative charge and higher content of carbohydrates are preferentially able to pass through the glomerular barrier, providing the descriptive basis of diabetic albuminuria. Their relevance to diabetic nephropathy is a goal for further work.
Double‐label autoradiography revisited: II. The 35S and 75Se‐system
Authors: McConkey Edwin H. , Anderson Catherine 
Published: May 2005

AbstractThe use of 75Se in combination with 35S for double‐label autoradiography has been quantitated. For gels 0.8 mm thick impregnated with EN3HANCE, the input ratio of 75Se dpm/35S dpm should be 3.3; and the second stage autoradiogram, if made with an interposed sheet of blackened XAR films as a screen to block 35S, should be exposed 7.8x as long as the flourogram for SB film or 5.6 × as long as the fluorogram for XAR film. However, autoradiograms made under these conditions have larger, more diffuse spots than those made with the 3H/35S system and the cost of [75Se]selenomethionine is much higher than the cost of [3H]methionine.
Separation of the primary isoenzyme bands (a±, b±) determined by the phosphoglucomutase (PGM1) locus on an immobilized pH gradient
Authors: Sutton John G. , Westwood Sara A. 
Published: May 2005

AbstractThis report describes a method of typing the phosphoglucomutase (PGM1) locus (EC 2.7.5.1) isoenzymes from bloodstains on an immobilized pH gradient. A pH 5.8 to 6.8 gradient was prepared in which only the primary typing bands, a± and b±, associated with the 10 common PGM1 locus phenotypes were separated. This system provides the forensic scientist with a method of typing anomalous results where confusion has arisen over the identity of the b+ and the c−/c+ isoenzymes observed by conventional electrofocusing. Successful typing of 2‐month‐old bloodstains was achieved within 2.0 h.
Rapid electrofocusing of erythrocyte acid phosphatase
Authors: Budowle Bruce 
Published: May 2005

AbstractA routine method is described for obtaining reproducible erythrocyte acid phosphatase patterns by ultrathin‐layer polyacrylamide gel isoelectric focusing. Electrofocusing of EAP on 0.2 mm thick gels took 30 and 22 min on the Ultrophor and Cold Focus Apparatus, respectively, when the distance separating the electrodes was 5.4 cm. This method, which reduces the cost for focusing EAP, can be ideal for many laboratories interested in EAP phenotyping.
pH gradient characteristics of commercially available carrier ampholytes and their uses for typing the human phosphoglucomutase locus (PGM1)
Authors: Gill Peter , Sutton John G. 
Published: May 2005

AbstractA number of different carrier ampholyte mixtures were compared in order to produce a pH gradient which separated the phosphoglucomutase‐1 (PGM1) phenotypes most efficiently. Ultrathin gels incorporating a mixture of pH 5–7 and pH 6–8 Ampholine was shown to produce the best results. Application of samples to the cathodal end of the gel reduced the problem of overloading which is frequently encountered with ultrathin gels.
Esterase D: Simultaneous electrophoretic determination of the three common allozymes (ESD 1, 2, 5)
Authors: Bär Walter , Häni Markus , Biedermann Verena 
Published: May 2005

AbstractA simple and time‐saving electrophoretic method for the determination of the 6 common phenotypes of red cell esterase D (ESD) is presented. Using a continuous buffer system composed of malic acid, the separation of the allozymes is accomplished at pH‐values between 5.35–5.45 by thin‐layer agarose gel electrophoresis in 4 h. Until now, a combination of electrophoresis and isoelectric focusing was required to obtain the same results. The economical advantage as well as the modest requirements concerning laboratory equipment are evident.
Analysis of free zone electrophoresis of fixed erythrocytes performed in microgravity
Authors: Snyder Robert S. , Rhodes Percy H. , Herren Blair J. , Miller Teresa Y. , Seaman Geoffrey V. F. , Todd Paul , Elaine Kunze M. , Sarnoff Burton E. 
Published: May 2005

AbstractA free fluid zone electrophoresis experiment was performed in the microgravity environment of Space Shuttle flight STS‐3 (March 1983). The experiment was designed to confirm observations made on the Apollo‐Soyuz mission of 1975 and to test the effect of high red blood cell (RBC) concentration on free fluid electrophoresis. Photographic documentation of cell zone progression in one‐hour separations of mixtures of formaldehyde‐fixed human and rabbit erythrocytes (RBC), which were subjected to a field of approximately 13 V cm−1 in low ionic strength buffer, was analyzed. One of two columns contained 2 × 108 RBC ml−1 (low concentration), and the other contained 1 × 109 RBC ml−1 (high concentration). The observed and calculated leading edge displacements of the RBC in the two columns were in agreement, indicating the absence of unexpected effects of the reduced gravity environment. Post‐flight analyses of the contents of the columns was not possible, and additional microgravity experiments are needed to evaluate the role of particle‐particle interactions in concentrated suspensions undergoing electrophoresis.
Preparative isoelectric focusing in immobilized pH gradients IV. Recovery of proteins from Immobiline matrices into ion‐exchange resins
Authors: Casero Patrizia , Gelfi Cecilia , Righetti Pier Giorgio 
Published: May 2005

AbstractA new electrophoretic transfer system for the recovery of proteins focused in Immobiline matrices is described. The gel strip containing the sample zone of interest is transferred to a horizontal tray and embedded in 1%, low‐gelling (37°C) agarose. For acidic to neutral proteins (up to pI 7.7) the electrophoretic transfer is from the IPG strip into a layer of DEAE‐Sephadex, buffered at pH 8.5 in 100 mM Tris‐acetate. Recovery (better than 90% in all cases studied) is achieved by titrating the resin at pH 9.5, in 200 mM Tris‐Gly buffer, containing 200 mM salt. For basic proteins (pI>7.7) the electrophoretic retrieval is from the IPG strip into a zone of CM‐Sephadex, buffered at pH 6.0, in 50 mM citrate (cathodic migration). Recovery (again better than 90%) is accomplished by titrating the exchanger at pH 4.0, in 200 mM formate buffer, containing 200 mM NaCl. Exposure to pH 9.5 does not affect enzyme activity if the eluate is promptly titrated around neutrality; a pH 4 milieu might irreversibly alter enzymes, in which case elution is best performed by titrating the protein to its pI, rather than protonating the exchanger. It has been demonstrated that Immobiline gels, even when incorporating 5 times the standard amount of buffer (75 mM Immobiline at pH = pK, i. e. 50 mM buffering ion and 25 mM titrant) exhibit, under the electric field, negligible ion‐exchange properties, thus ensuring ideal behavior as supports for isoelectric focusing.
Computer‐aided analysis of the electrophoretic regulating function omega
Authors: Thormann Wolfgang , Mosher Richard A. , Bier Milan 
Published: May 2005

AbstractThe omega function, defined for strong and monovalent weak electrolytes, is a useful regulating principle for the description of electrophoretic processes. The omega function profile, which is established by the initial electrolyte distribution in an electrophoretic column, will not be changed by current flow. The function is based solely upon migration and is only applicable to those regions where diffusional dispersion can be neglected. Computer simulations are used to follow the evolution of the concentration gradients of various electrophoretic systems and to verify the proposed constancy of the omega function profile. The limitations of the theory are investigated and the value of these predictions to the experimentalist is discussed.
A two‐dimensional electrophoretic profile for bacterial esterases
Authors: Goullet Philippe , Picard Bertrand 
Published: May 2005

AbstractEsterases produced by different bacterial species were separated by conventional electrophoresis (CE) in polyacrylamide agarose gel and by thin‐layer isoelectric focusing (IEF). Although CE revealed the greatest number of esterases and was preferable for their identification by specific hydrolytic activities, the two techniques appeared to be complementary in their resolving power for detection of electrophoretic variants. Consequently, by establishing a direct correspondence between homologous esterase bands resolved by CE and IEF, we have proposed a two‐dimensional electrophoretic profile (2‐DEP) which considerably refined the degree of esterase polymorphism and improved the enzymic differentiation between and within bacterial species.