Clonogenic survival assay.

Cells were seeded at 5,000 per well into 6-well plates and continuously treated with the PARP inhibitor at mentioned concentrations. Colony forming units were stained 14 days after treatment using 0.5% (w/v) crystal violet in methanol. Cell count was performed for 0.1 μM concentration of olaparib, where cells were at 10000 per well in 12 well plate in triplicate. After 14 days on olaparib treatment, cells were trypsinized, harvested, and counted using Beckman coulter counter. Cell survival was estimated by normalizing all values to values from respective DMSO treated wells. Each well was counted thrice, and the average was taken. For each time point, an average of three independent wells was plotted.