Effect of topical CEES exposure on DNA oxidation in SKH-1 hairless mouse skin. Mice were treated topically with 2 mg of CEES or acetone alone, and the dorsal skin was collected at specific time points as detailed under Materials and Methods. Skin tissue DNA from time-response study was extracted and 8-oxo-2-deoxyguanosine (8-OH2dG) was measured by HPLC-EC as described under Materials and Methods. Data was reported as the ratio of 8-OH2dG/105 2dG. *, p<0.001; $, p<0.02; #, p<0.05 as compared to untreated control group (n=3–5). UC, untreated control; VC, vehicle control.