Figure 1.

Flow chart for the identification of genotoxic compounds. One hundred and nineteen compounds with ≥3-fold increase in cytotoxicity (P < 0.05) in the KU70 ^−/−/RAD54 ^−/− and/or REV3 ^−/− cells compared with wild-type cells were identified in the primary screening. Sixty-three of the 119 compounds were confirmed in a replicate qHTS cells viability assay using the same 3-fold differential cytotoxicity measure. Eight compounds were selected from the 63 based on their novelty, commercial availability and potency of the differential cytotoxicity response for further testing in in vitro γH2AX immunostaining and MN assays.