17] Zone electrophoresis with polyacrylamide gel

Abstract

This chapter discusses the method of zone electrophoresis with polyacrylamide gel. Polyacrylamide gel is a synthetic support medium for electrophoretic separation of proteins. It is prepared by copolymerizing acrylamide and N,N’ -methylenebisacrylamide in the apparatus in which the electrophoresis is to be carried out. This gel has properties similar to starch or other gels: superimposed on normal electrophoretic separation based on charge is the additional separation on the basis of size and shape. Polyacrylamide gel appears to offer certain advantages over other gels as a support medium in zone electrophoresis. Polyacrylamide gel gives the same kind of separation patterns in general as obtained with other media, but apparently this gel is superior in resolving power over other gels in current use. The equipment requirements and procedure of polyacrylamide gel electrophoresis is provided. After the apparatus is assembled, a thin gel is formed in the space between the cooling plates while the cell is in a horizontal position. Another analytical technique widely used is disc electrophoresis. In this apparatus, a multilayered polyacrylamide gel is formed: the large-pore gels are for introduction and concentration of the protein; electrophoretic separation takes place in the final, small-pore gel. The chapter also discusses some of the properties of preparative electrophoresis.