Band Sharpening by Acid in Polyacrylamide Gel Electrophoresis

When we used an acidic solution of BPB as a marker for tracking, we observed that the band of the dye sharpened to become a very thin line. We supposed that the sample proteins in the gel should be similarly concentrated by the action of acid, and that the resolution should be improved. Among the acids we assessed, most of which sharpened the BPB band, 2 M acetic acid showed the proper band sharpening action and brought about the improvement in resolution.