Fig. 5.

Differences of singlet oxygen production rate & cell death between SW480 and SW480/ABCG2 cells. a, SW480, SW480/ABCG2, and HT29 cells were incubated with 100 nM PPa for 16 h and then lysed with methanol, followed by application of PMT-based singlet oxygen monitoring system. b, Cells were harvested 4 h after photosensitization and stained with Annexin V/PI for FACS analysis. c, Cells were incubated with 100 nM PPa for 16 h followed by irradiation. Cell lysates were subjected to immunoblot with indicated antibodies. Data are means ± SEM from three independent experiments (^*P < 0.05, ^**P < 0.01, ^#P < 0.0001)