The induction of apoptosis by TMZ, Qct or combination treatment. DB-1 cell lines were subjected to varying dose of A) TMZ treatment (0-400 μM) for 48 hrs or B) Qct treatment for 24 hrs (0-100 μM). The cells were subjected to apoptotic analysis by Annexin/FITC staining by using BD FACS flow cytometer and the percentage of apoptosis was determined. C) The stacked percentages of apoptotic cells after TMZ treatment in DB-1 or D) SK Mel 28 cell lines Results are mean of duplicate experiments. E) Representative flow cytometric scatter plots of DB-1 cells. Early apoptotic cells can be visualized in the lower right quadrant, while late apoptotic/necrotic cells are shown in the upper right.