EGFR Activation Serum starved MDA-MB 468 cells were incubated with 10 ng/ml EGF for the indicated times. Whole cell lysates were prepared with lysis buffer V19 and separated by SDS-PAGE (ca 20.000 cells/lane). The immunoblot was probed with mab EGFR-11C2 (0.5 ug/ ml) for 1 h at RT and developed by ECL (exp. time: 30 sec). Lane 1: Control; Lane 2: 5 min EGF; Lane 3: 15 min EGF; Lane 4: 30 min EGF; Lane 5: 1h EGF; Lane 6; 2h EGF; Lane 7: 4h EGF; Lane 8: 8h EGF.