Detection of endogenous MEK1 Whole cell lysates of serum starved tumor cells (20000 cells per lane) were applied to SDS-PAGE and transferred to PVDF membranes. Immunoblots were probed with mab 10B1 (0.5 ug/ ml) for 1h at RT and developed by ECL (exp. time: 30 sec). lane 1: HeLa; lane 2: HepG2; lane 3: HEK293; lane 4: SH-SY5Y; lane 5: MDCK; lane 6: PC12; lane 7: CMT 93; lane 8: Neuro 2A; lane 9: 3T3