Phosphospecificity Whole cell extracts of control (co), EGF-stimulated (EGF) or pervanadate-treated (VH) A549 tumor cells were applied to SDS-PAGE (ca. 20.000 cells per lane) and transferred to a PVDF membrane. The immunoblot was probed with mab shc-1E3 (0.5 ug/ ml) for 1h at RT and developed by ECL (exp. time: 30 sec).