Protocol describes a method for performing isoelectric fractionation of a maize embryo sample using a multicompartment electrolyzer(MCE). This prefractionation of proteins having pIs within a certain pH interval is essential for allowing high loads of protein to be resolved on narrow and ultra-narrow immobilized pH gradients used in 2D electrophoresis. The isoelectric membranes in the MCE act like isoelectric traps capturing all the protein species having pIs encompassing the pI value of each...
