Oligomycin abrogates drug-induced apoptosis in MOLT-3 cells. (A) Cascade of apoptotic events (indicated by arrows) as characterized by MTMP loss (JC-1 staining), activation of caspase-3 (immunofluorescence), and annexin V staining (annexin V/PI test) (JC-1, caspase-3, annexin V and PI fluorescence: 4-decade log scaling). MOLT-3 cells were incubated with etoposide (1 μM) and oligomycin (10 μg/mL) for 6 hours. (B) Kinetics of apoptotic events in MOLT-3 cells incubated with etoposide (1 μM) with or without oligomycin (10 μg/mL). □ indicates MTMP loss; □ indicates act. Caspase-3; ▪ indicates annexin V+.