Figure 3: Flow cytometric analysis of RPMI-8226 cells stained with Hoechst 33342. (a) The proportion of viable cells started to decrease when dye concentration exceeded 15 μg/mL. (b) Flow cytometry profiles of SP analysis changed over dye concentration from 1 to 50 μg/mL. (c) In another experiment with Hoechst 33342 concentration ranging from 7.5 μg/mL to 20 μg/mL, SP% dropped sharply from 26.3% at 7.5 μg/mL to 0.16% at 12.5 μg/mL. Data are mean ± SD value of triplicate samples in an independent experiment. Bar indicates standard deviation. The experiment was repeated at least three times with similar results. One of the three independent experiments is shown as representative data.