Fig. 1
![Fig. 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs41021-015-0014-8/MediaObjects/41021_2015_14_Fig1_HTML.gif)
Experimental design. a In the absence of DNA damage, RNA polymerase generates RNA transcripts from DNA templates (normal transcription). After purifying RNA, RT-PCR is performed, and the PCR products are analyzed. b If chemical substances damage DNA, the resulting lesions inhibit RNA synthesis, as RNA polymerase cannot synthesize transcripts from damaged templates, and PCR products will not be detected