Three hundred ng of HeLa whole cell extract was incubated with 0, 50 or 100 μM of the indicated inhibitor at room temperature for 15 min, prior to the addition of 0.5 pmol radiolabeled AP-DNA substrate and subsequent transfer of the reaction mix (final volume of 10 μL) to 37 ºC for 5 min to allow for incision. Following addition of stop buffer and heat denaturation, the reaction products were subjected to 15% polyacrylamide denaturing gel electrophoresis. Shown is a bar graph reporting the relative percent incision activity in comparison to the no inhibitor control, arbitrarily set at 100. The values reported represent the averages and standard deviation of three independent experimental data points.