2-D Electrophoresis
In 2-D electrophoresis, proteins are separated in the first dimension, according to their isoelectric points, by IEF, and in the second dimension, according to their molecular weights, by SDS-PAGE24,25. The first, IEF, stage is conducted in a long, thin, spaghetti-like gel. This gel must be of large pore-size so that focusing is possible, but this makes it very soft and fragile. For the second stage the long, thin, gel is transferred to the origin of a slab gel, sealed in position and an SDS-PAGE separation is carried out. The result, after staining, is a number of spots distributed in two dimensions over the slab gel. Because the first-stage gel is of a small diameter, only a small amount of ampholytes is consumed per run and so 2-D electrophoresis is relatively inexpensive.
Although conceptually simple, it took a number of years for the method to be developed to its present stage of practicability. One of the technical difficulties to be overcome was the handling and transferal of the first-stage gel soft spaghetti is not the easiest type of material to handle!
References
Dennison, C. (2002). A guide to protein isolation . School of Molecular mid Cellular Biosciences, University of Natal . Kluwer Academic Publishers new york, Boston, Dordrecht, London, Moscow .
Garrels, J. I. (1 983) Quantitative two-dimensional gel electrophoresis of proteins. Methods Enzymol. 100, 41 1-423.
Dunbar, R. S., Kimura, H. and Timmons, T. H. (1990) Protein analysis using high-resolution two-dimensional polyacrylamide gel electrophoresis. Methods Enzymol. 182, 441-459.
