Fig. 1.

Analysis of apoptotic cell death during HL-60 differentiation. HL-60 cells were incubated with or without DMF (0.8%), ATRA (1 µM), or VitD₃ (20 µg/mL) for the indicated time period. Cells were stained with 20 µg/mL of 7-AAD and percentage of apoptotic cell populations were determined by analyzing fluorescence intensity of moderately stained cells with flow cytometry. ^*Indicates P < 0.05 when the values were compared with that of the day 0. DMF, dimethylformamide; ATRA, all-trans retinoic acid; VitD₃, vitamin D₃; 7-ADD, 7-aminoactinomycin D.