Figure 6.

Absolute quantification of UV photoproducts in vivo. (A) Excised oligonucleotides containing UV damage were recovered from A375 cells 1 h following exposure to 10 J/m² of UV-C. The purified oligonucleotides were then either biotinylated or radiolabeled as in Figure 5 using Hirt lysate-purified DNA from a defined number of cells. As a standard for quantification of the excised oligonucleotides, a 20-nt long single-stranded DNA oligonucleotide was either biotinylated or radiolabeled and then electrophoresed and analyzed with the UV photoproduct-containing excised oligomer repair products. (B) Absolute quantification of the excised repair products in vivo. The results from two independent experiments were quantified and are plotted (means ± standard deviation).