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. 2008 Oct 13;99(10):2019–2027. doi: 10.1111/j.1349-7006.2008.00910.x

Figure 1.

Figure 1

Photodynamic therapy (PDT) with methylene blue (MB) induces apoptosis in B16F1 cells. (a) Cell viability was determined by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) assay 18 h after treatment of MB‐PDT (ranging from 0 to 25 µM). Results are expressed as the percentage of viable cells compared with light alone‐treated control (mean ± SD, n = 3). (b) Apoptosis in B16F1 cells was assessed at 6 h post‐treatment by annexin V‐FITC/PI binding and measured by flow cytometry analysis. Numbers indicate the percentage of cells in each quadrant. (c) B16F1 cells were pretreated with 50 µM benzyloxycarbonyl‐Val‐Ala‐Asp (Z‐VAD‐FMK) or the caspase inhibitor Z‐DEVD‐FMK for 1 h followed by treatment with MB‐PDT, then apoptosis was determined by flow cytometry at 6 h post‐treatment.