Figure 4

Measurement of apoptotic cells under VP-16 (30 μM) treatment for 6 h determined by FACS analysis. (A): untreated (control) cells; (B): cells treated with A23187 at 2 μM for 24 h; (C): cells pretreated with BAPTA-AM at 40 μM for 2 h prior to the addition of A23187 at 2 μM for 24 h. The cells were labeled with annexin V and PI. Viable cells were those with low annexin or no annexin and PI staining (lower left panel). Early stage apoptotic cells were represented by high annexin and low PI staining (lower right panel), later stage apoptotic cells were represented by high annexin and high PI staining (upper right panel), and necrosis cells were represented by high PI and low annexin staining (upper left panel).