DIFFERENCE GEL-ELECTROPHORESIS - A SINGLE GEL METHOD FOR DETECTING CHANGES IN PROTEIN EXTRACTS

We describe a modification of two-dimensional (2-D) polyacrylamide gel electrophoresis that requires only a single gel to reproducibly detec t differences between two protein samples. This was accomplished by fl uorescently tagging the two samples with two different dyes, running t hem on the same 2-D gel, post-run fluorescence imaging of the gel into two images, and superimposing the images. The amine reactive dyes wer e designed to insure that proteins common to both samples have the sam e relative mobility regardless of the dye used to tag them. Thus, this technique, called difference gel electrophoresis (DIGE), circumvents the need to compare several 2-D gels. DIGE is reproducible, sensitive, and can detect an exogenous difference between two Drosophila embryo extracts at nanogram levels. Moreover, an inducible protein from E. co li was detected after 15 min of induction and identified using DIGE pr eparatively.