Localization of separated protein bands in unstained electrophoresed polyacrylamide gradient slab gel

Polyacrylamide gel electrophoresis has become the most widely used separation method in biological science. Once electrophoresis is complete the protein bands must be localized prior to excision. A zig-zag gel cutter is described which cuts a strip of gel from the side of a slab gradient gel or a gel of uniform concentration in peaks and valleys. The location of the protein of interest is determined by counting the number of peaks on the stained side strip. The portion of the unstained gel corresponding to the same count (number of valleys) is cut to recover the protein of interest from the main gel for further manipulations.