Figure 4.

Formation of the spore photoproduct within UV-irradiated freeze-dried DNA. The lesion was quantified as dinucleoside monophosphate (TpT, intra-strand) or thymidine (Thd, inter-strand) dimeric photoproduct in enzymatically digested DNA. The reported level of Thd spore photoproducts represents the sum of the amount of the two diastereoisomers. The total level of spore photoproduct, released as a thymine lesion, was measured in acid-hydrolyzed DNA samples. Results represent the mean ± SD of three independent experiments.