FVIIa prevents activation of caspase 3 in serum-deprived cells. (A) Monolayers of BHK(+TF) cells were incubated in SFM in the absence or presence of FVIIa (100 nM) for 0.5, 1, 2, 3, 4, or 5 hours. At the end of incubation, the cells were collected and lysed. Equal amounts of protein (10 μg) were subjected to SDS-PAGE followed by Western blot analysis with anti–caspase 3 antibody. The blots were stripped and reprobed with a β-actin–specific antibody as a measure of equal loading. (B) Wild-type BHK cells were treated with SFM or the SFM supplemented with FVIIa (100 nM) or serum (10% vol/vol) for 4 hours, and the cells were processed as described for panel A. (C) CHO(+TF) cells were incubated in SFM or the SFM supplemented with FVIIa (100 nM) or serum (10% vol/vol) for 4 hours, and the cells were processed as described for panel A. (D) CHO-K1 wild-type cells were incubated in SFM or the SFM supplemented with FVIIa (100 nM) or serum (10% vol/vol) for 4 hours, and the cells were processed as described for panel A. The figure shows a representative Western blot of 3 independent experiments.