Disc electrophoresis

Disc Electrophoresis. Resolution in zone electrophoresis depends critically on getting sample components to migrate in a focused band, thus some techniques ate employed to concentrate the sample as it migrates through the gel. The most common technique is referred to as discontinuous pH or disc electrophoresis. Disc electrophoresis employs a two-gel system, where the properties of the two gels are different. 

Disc electrophoresis was first iatroduced ia the early 1960s (11—13) as various techniques using polyacrylamide gels were being explored and designed. Original work employed several buffer systems and different polyacrylamide gels in order to first concentrate and then separate compounds (14). 

Another difference between other types of electrophoresis and disc electrophoresis is that the molecules in a sample do not start to significantly separate until entering the separating gel. A discontinuous gel system may be used with almost any type of 2one electrophoresis appHcation. 

Ornstein, L, Disc Electrophoresis—I Background and Theory, Annals of the New York Academy of Sciences 121, 321, 1969. 

Ornstein, L Davis, BJ, Disc Electrophoresis Distillation Products Div., Eastman Kodak Co. Rochester, 1962. 

In the purification of pectinesterase from the fruits of Citrus nat-sudaidai,61 fractional salting-out with ammonium sulfate was followed by chromatography on a column of DEAE-cellulose and by separation of the active fraction on Sephadex G-100. A preparation (purified solution) having a specific activity 460-fold greater than that of the original extract was obtained. Its homogeneity was checked by disc electrophoresis, and its amino acid content was determined and fundamental, kinetic data were obtained. 

Miller and Macmillan49 purified pectinesterase produced by Fusarium oxysporum f. sp. vasinfectum by chromatography on DEAE-Sephadex A-25, Sephadex G-75, CM-Sephadex C-50, and CM-cellulose. The homogeneity of the pectinesterase obtained was confirmed by disc electrophoresis an apparent molecular weight of 35,000 was estimated by its behavior on a column of Sephadex G-75 (Superfine). 

The highest degree of purification was achieved with extracellular endopectate lyase from the anaerobic bacterium Clostridium fel-sineum.Mi A 225-fold purified preparation, homogeneous in disc electrophoresis, was obtained by precipitation with ethanol, and chromatography on CM-cellulose and on Sephadex G-200. Its molecular weight (determined by gel chromatography) was 105,000. 

G6. Garoff, H., Simons, K., Ehnholm, C., and Berg, K., Demonstration by disc electrophoresis of the lipoprotein carrying the Lp(a) antigen in human sera. Acta Pathol. Microbiol. Scand. B7S, 253-254 (1970). 

The Laemmli SDS-PAGE protocol is one of the most important analytical techniques in analytical protein separation. It is a system with discontinuous pH gradient (disc electrophoresis) and consists of a stacking and a separation gel different in acrylamide concentration and pH. The separation gel may be formed with homogenous acrylamide concentration or with an increasing gradient. 

Figure 2. Protein pherograms (disc electrophoresis) of different grape varieties (harvest 1971). The separation distance was redrawn to a 10 cm scale. Scale Rf-values, Arrows Main bands common to all varieties.

The amino acids were analyzed from the press juices of the berries by an amino acid analyzer with ion-exchange columns as previously reported (17, 18). We described in detail the methods of disc electrophoresis and the isoelectrical focusing in polyacrylamid gels in another publication (8). 

Davis, B.J. 1964. Disc electrophoresis II Method and application to human serum proteins. Ann. N. Y. Acad. Sci. 121 404-427. 

Figure 8. Polyacrylamide-gel disc electrophoresis of Ex-1. Electrophoresis of the purified enzyme was carried out by the method of Weber and Osborn, using 10% acrylamide, pH 7.0, containing 0.1M sodium phosphate and O.IM sodiumdodecyl sulfate.

Maurer, H. R. In Disc Electrophoresis and Related Techniques of Poly-... 

More recently, Manabe (3A) purified PE from Citrus natsudaidai fruit by chromatography on a DEAE-cellulose column followed by Sephadex G-100 column adsorption of the active fraction. The final preparation was homogeneous as determined by disc electrophoresis and was A60 times as active as the original extract on a protein basis. 

Abildgaard U, Highly purified antithrombin III with heparin cofactor activity prepared by disc electrophoresis. Scand J Clin Lab Invest I 968 21 89-91. 

Mikulikova, L. (1979). Identification of helminth species by means of disc electrophoresis. Folia Parasitologica, 26 111-22. 

Comparative study of protein spectra in cestodes and their hosts by means of gel chromatography and disc electrophoresis.] In Russian Parazitologyia, 18 430-5. [HA/54/1725]... 

Discontinuous zonal electrophoresis, known as disc-electrophoresis for short, is the electrophoretic technique that is most often used in protein analysis. The method, originally developed by Omstein and Davis, has given rise to several derivative techniques, notably the well-known SDS-PAGE method of Laemmli (1970). The technique is thoroughly covered in the literature, reflecting its importance in protein... 

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