siRNA oligonucleotide targets that are synthetically lethal with CHK1 inhibition by Gö6976. (A) Schematic for identification of siRNA oligonucleotides that exhibited selective toxicity when combined with CHK1 inhibition by Gö6976 (i.e. synthetic lethality). Cells were plated on day 1. On day 2, each well was transfected with an siRNA oligonucleotide directed toward one DNA damage response/repair gene. On day 3, one set of cells was treated with Gö6976 (Calbiochem) at a concentration of 500 nM. The other set was treated with DMSO. On day 6, the viability of the cells in each well was measured using the Cell Titer-Glo Luminescent Cell Viability Assay kit (Promega). (B) The top 30 gene targets from the genetic screen. The top 30 targets where both independent siRNAs caused toxicity when combined with Gö6976 treatment are shown in Figure 2B. Viability and standard deviation calculation are calculated as described in Methods. Genes integral to FA pathway function are indicated in red.