Induction of apoptosis and expression of CD95 (FAS/APO-1) receptor in Daudi cells in the absence or presence of IFN-α.

Cells were incubated without or with 200 U/mL IFN-α for 1, 3, and 5 days. Cells were then subjected to double staining for Tdt-mediated dUTP-biotin nick-end labeling (TUNEL) and CD95 expression and flow cytometry analysis. The population of TUNEL⁺/CD95⁺ cells was gated in the analysis by the use of negative control antibodies. Data are representative of 1 of 4 experiments.