Difference gel electrophoresis. A single gel method for detecting changes in protein extracts

TLDR

The study introduces a single‑gel 2‑D polyacrylamide electrophoresis method to detect differences between two protein samples. The method uses two distinct fluorescent dyes to label the samples, runs them together on one 2‑D gel, images the gel in two channels, and overlays the images, with dyes engineered to preserve identical mobility for shared proteins. DIGE eliminates the need for multiple gels, is reproducible and highly sensitive, detecting nanogram‑level differences between Drosophila embryo extracts and identifying an inducible E.

Abstract

We describe a modification of two-dimensional (2-D) polyacrylamide gel electrophoresis that requires only a single gel to reproducibly detect differences between two protein samples. This was accomplished by fluorescently tagging the two samples with two different dyes, running them on the same 2-D gel, post-run fluorescence imaging of the gel into two images, and superimposing the images. The amine reactive dyes were designed to insure that proteins common to both samples have the same 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. coli was detected after 15 min of induction and identified using DIGE preparatively.