A simplified method of protein electroblotting after isoelectric focusing on an ultrathin polyacrylamide gel layer fixed on a cellophane support.

A method is described for isoelectric focusing of proteins, using an ultrathin-layer polyacrylamide gel on cellophane, followed by electrophoretic transfer of separated proteins onto a nitrocellulose membrane. The polyacrylamide gel is firmly attached to the cellophane and thus protected from mechanical damage; such gels are easily manipulated. Cellophane is permeable to ions and application of this gel support overcomes difficulties resulting from the removal of ultrathin gels from a plastic support on electroblotting. Proteins separated under nondenaturing conditions were transferred onto a nitrocellulose membrane and detected by the concanavalin A-peroxidase technique. The proposed approach makes it possible to analyze the variability of nondenatured proteins and glycoproteins of different origin.