Fig. 4.

Effect of Ptpp-PDT on induction of apoptotic cell death in NOZ cells. (A) Apoptosis and necrosis were analyzed by flow cytometry using annexin V-FITC and PI at different time points (0–24 hr) after Ptpp-PDT. (B) Data were obtained from three independent experiments and results are shown as a bar graph. Annexin V-positive/PI-positive and -negative cells are apoptotic, and annexin V-negative/PI-positive cells are necrotic. *P < 0.05, **P < 0.01 vs. 0 hr. Data are shown as the mean ± SD of three independent experiments. (C) Apoptotic cells were examined by TUNEL assay at 0 and 24 hr after Ptpp-PDT. Green and blue colors represent TUNEL-positive cells and DAPI, respectively. Bar = 10 μm.