Staining of Preparative 2-D Gels: Coomassie Blue and Imiciazole-Zinc Negative Staining

The identification of proteins using preparative gel electrophoresis and mass spectrometry requires reversible staining of relatively thick (1–1.5 mm) polyacrylamide gels. We have found that staining with colloidal Coomassie brilliant blue G-250 or negative staining with imidazole-zinc yields high-resolution stains (Fig. 1) that are compatible with subsequent mass spectrometric analysis (see Notes 1 and 5).