A discontinuous electrophoretic system for separating peptides on polyacrylamide gels

An electrophoretic system for separating, with high resolution, peptides 25–250 residues in length is described. The peptides are stacked by discontinuous electrophoresis to form very sharp bands at the origin. They are then separated on a matrix of 20% polyacrylamide, 8 m urea, and 0.1% dodecyl sulfate. Through this combination, high resolution and clean separation, based on polymer length, are achieved.