Quantitation of extent and type of H₂O₂ -induced cell death induced in bcl-2–transfected JLP 119 cells by Hoechst/propidium iodide nuclear staining. JLP 119 cells transfected with either control plasmid (G4 and G21) or plasmid expressing the bcl-2 gene (H6 and H10) were treated with 100 μmol/L H₂O₂ or 5 μg/mL etoposide. In both cases, cells were collected after 24 hours and examined for cell death (propidium iodide staining) and morphologic features of apoptosis (chromatin condensation) as described in the Materials and Methods. The data represent the average of four independent experiments. (▪) Necrotic death; (▨) apoptotic death.