Flow cytometric analysis of JLP 119 and EW-36 treated with A23187. (A) Flow cytometer plots. Cells (5 × 105/mL) were incubated in growth medium containing the indicated concentrations of A23187 (0, 0.5, 1.0, or 2.0 μmol/L) for 48 hours. FACS analysis of fixed cells was performed as described in the Materials and Methods. Rows 1 and 3, cytograms showing forward and side light scatter (FSC and SSC, respectively) for 10,000 cellular events. Rows 2 and 4, histograms of FITC-labeled DNA for the cells shown in the cytograms. Rows 1 and 2, results for JPL-119. Rows 3 and 4, results for EW-36. The population with high FITC intensity in each histogram (right-hand peak) represents apoptotic cells. The data shown are from a representative study that was repeated three times. (B) Proportion of JLP 119 (▴) and EW-36 (▵) cells that are undergoing apoptosis at each concentration of A23187. The percentage of apoptosis equals the high FITC-labeled population divided by the total cell population. Each point is derived from 10,000 cellular events and represents the mean ± SEM of triplicate cultures.
