Use of electroblotting to detect and analyze phosphotyrosine containing peptides separated by two-dimensional gel electrophoresis.

A technique to detect and analyze phosphotyrosine containing peptides after separation of total cellular proteins by two-dimensional gel electrophoresis is described. This is achieved by electroblotting of proteins on nylon membranes followed by alkali treatment. In comparison with direct alkali treatment of the polyacrylamide gel, this procedure is easier to perform; avoids the diffusion of proteins out of the gel during alkali treatment; allows a more precise localization of phosphotyrosine containing peptides on the untreated membrane; and is less time consuming with respect to extraction of proteins for phosphoamino acid analysis.