Figure 6.
(A) The NER dual incision activity of cancer cells extracts. Model DNAs were incubated for 30 min at 30°C with cell extracts prepared from HeLa, C33A or SiHa cells (20 nМ DNA, 1.6 mg/ml of extract proteins and 500 nM template 1). The excision products were detected by annealing to template followed by end-labelling using α-[32P]-dCTP and Taq DNA polymerase. The reaction products were resolved on a 10% denaturing polyacrylamide gel. Non-modified 137-bp DNA was used as a negative control; 32P-labelled oligonucleotides were used as size marker. (B) Densitometric analysis of the lanes 5 (HeLa, left), 8 (C33A, middle) and 11 (SiHa, right).