Cleavage of CPyD-containing DNA by the in vitro transcription/translation product. The pUC18 substrate was treated by photosensitization (A) or 254-nm irradiation (B). Two-microliter portions of the translation mixtures (total volume, 50 μl) were used for the assay. Even-numbered lanes, treated substrate; odd-numbered lanes, untreated substrate. Lanes 1 and 2, substrate alone. Transcription templates: pT7T3 18U (lanes 3 and 4), pT7UVE211 (lanes 5 and 6), pT7UVE21 (lanes 7 and 8), and pT7UVE21R (lanes 9 and 10). cc, closed circles; oc, open circles.