Figure 4.
Checkpoint kinase 1 (CHK1) phosphorylation in NHF1 exposed to UVA–UVB or UVC. Fluences of UVA–UVB or UVC were chosen so as to produce equivalent CPD burdens. a) Immunoblot showing P-CHK1 (S345), total CHK1 and ACTIN. b) Quantification of immunoblots (n = 3) by densitometry ±SEM. Densitometry values were normalized to the highest ratio of P-CHK1:total CHK1 in each experiment. The normalized ratios of P-CHK1 to total CHK1 produced by the UVA–UVB source (open bars) were not statistically different (Wilcoxon rank-sum test) from those produced by UVC (filled bars) at equal CPD densities.
