pI-Control in comparative fluorescence gel electrophoresis (CoFGE) using amphoteric azo dyes

Abstract

Gel-to-gel variation is a major problem in two-dimensional (2D) gel electrophoresis. Vertical and horizontal comparative fluorescence gel electrophoresis (v/hCoFGE) were recently introduced to improve the reproducibility of protein spot assignment. There, in a combination of 1D- and 2D-PAGE, protein analytes were overlaid with a reference grid which allowed correcting for variation in the y-direction. However, control of the first dimension, pI (x-direction), was missing so far. Here, we applied amphoteric azo dyes for this purpose completing the CoFGE toolkit.