Surviving populations of BAK, STU, and BUL melanoma cells show increased CD133 positivity. After cells were exposed to 1 μM of T for 72 h, drug resistant cells were subjected to immunofluorescence staining with PE-conjugated CD133/epitope 2 antibody, counterstained with DAPI, and visualized by fluorescence microscopy. Representative images are shown along with 5-fold magnified insets (lower left of each panel) showing membrane localization of CD133 (a). The percentage of CD133(+) cells (red arrows) in each drug-resistant population was quantified and plotted (b). Error bars represent mean ± SD for triplicates. Experiments were performed three times; a representative experiment is shown.