Effects of DNR, IDR, and MTA on HL-60 and CEM cells as measured with the Annexin V binding assay, the ³H-TdR incorporation assay, and the MiCK assay of apoptosis. HL-60 cells were exposed to 0.1 mm DNR for 36 hours and to 0.5 μmol/L IDR or 2.5 μmol/L MTA for 6 hours. CEM cells were exposed to 2.5 μmol/L DNR for 16 hours and to 5 μmol/L IDR or 5 μmol/L MTA for 7 hours. (A) Flow cytometry analyses of Annexin V-FITC/PI stained cells; 5,000 cells were analyzed in each condition. Quadrants were set using negative controls. The lower left quadrants of the cytograms show viable, An⁻PI⁻, cells. Numbers in the lower right quadrants refer to the percentage of apoptotic cells with preserved plasma membrane integrity (An⁺PI⁻, early apoptotic cells). Upper right quadrants show cells that have lost their plasma membrane integrity and became An⁺P⁺. The results of one of three independent experiments are shown. (B) Percentages of drug-induced inhibition of ³H-thymidine incorporation in HL-60 and CEM cells. Mean (±SD) of three independent experiments, each performed in three replicates. (C) Extent of apoptosis in drug-treated cells as determined with the MiCK assay of apoptosis. Results of the MiCK assay in KU were converted into percentages of apoptotic cells. Mean (±SD) of three independent experiments.