Relationship between KU of apoptosis and percentage of cells with apoptotic morphology. HL-60 (○) or CEM (•) cells were exposed to the drugs and distributed in two 96-well microtiter plates. One plate was placed into an incubated spectrophotometer and apoptosis was studied in the MiCK assay as described in Materials and Methods. The second plate was incubated in a humidified CO2-incubator. At the time points when the MiCK assay reported maximum apoptosis, cytospin preparations were made from cell aliquots from appropriate wells of the second plate. Apoptosis was measured with the MiCK assay in KU and determined microscopically in Giemsa-stained preparations as described in Materials and Methods. A total of 50 cell cultures exposed to various inducers of apoptosis were studied.
