Figure 3. Validation of oligonucleotide construct for measuring NER activity by using cell-free lysates.

CPD-containing oligonucleotides (150 million molecules) were incubated in the solutions of three reaction conditions: alone, with 293T cell lysates or with 293T lysates including anti-XPA antibodies at 30°C for 2 h. Quantification of the PCR-amplifiable, repaired oligonucleotides shows the background number of the detected oligonucleotides is 135. Incubation with cell lysates increased the number to 12,000 and addition of anti-XPA antibodies decreased the number to 5,000, suggesting that the assay is specific to the NER activity. Data were presented as mean ± S.D. from three independent experiments and P-value was calculated by t-test.