Fig. 8. (A) Phase contrast image of confluent sheet of HaCaT epithelial cells exposed to 10 μM DC324 and the righthand area of the field irradiated with UV-A. Image captured 10 minutes post irradiation; note that cell death occurred only in the irradiated zone. Scale bars equal 100 μm. (B) Cell viability after irradiation with varying UV-A doses. Dose–response curves have been fitted to the data in a box-whisker plot graph using 4 experimental replicates (n = 4). Statistical significance was determined by one-way ANOVA (p < 0.0001) and Dunnett's multiple comparison test comparing individual dose response curves to unirradiated controls (0 J cm^–2). The energy fluence of 14, 28 and 42 J cm^–2 were considered statistically significant with p values of 0.0034, 0.0002 and <0.0001, respectively. (C) The average viable fraction of HaCaT epithelial cellular populations 24 hours after an initial 60 second UV-exposure, as a function of the concentration of compound administered. A non-linear regression curve is fitted to the data (experimental replicates, n = 3; R² = 0.99).