Induction of apoptotic cell death in CD95 expressed 185-4 cells. The 185-4 cells were cultured with aggregated IgG (50 μg/mL), PMA (100 ng/mL), or rIL-3 (50 U/mL) as the negative control. After 24 hours, 1 × 10⁶ cells were exposed to 1 μg/mL of anti-CD95 (Jo-2) MoAb and incubated for the indicated periods. Cells were then stained with PI. Percentages of apoptotic cells were determined using an EPICS PROFILE flow cytometer. A representative of three experiments is shown.