Figure 3

Effect of pH using 0.5% H2O2 in Tris-HCI buffer at 80 °C for 15 min in FFPE tissue specimens of human malignant melanoma. (a) Representative H&E images obtained for 0.5% H2O2 in Tris-HCI buffer with pH 4, 6, or 10. The boxed regions are displayed at high magnification in the right panel (scale bar: 100 μm). (b) Bar graph of melanin pigment after bleaching. Melanin pigments were measured using image analysis software (Visiopharm). After bleaching, the highest pH (10) showed the lowest histoscore compared with pH 7 (P<0.001) and pH 4 (P<0.001). Data are depicted as mean±s.d. from three experiments.