A Mammalian Genetic Complementation Assay for Assessing Cellular Resistance to Genotoxic Compounds.

A complementation assay was developed to determine whether alleles of DNA repair genes are necessary for repairing specific types of damage. The assay was established by measuring the resistance capacity of Rad51d-deficient mouse embryonic fibroblasts (MEFs) transfected with mammalian expression constructs. Here, we describe the methods used to assess colony survival following the treatment of transfected cells with genotoxic compounds. This approach provides a time-efficient and stringent strategy to screen genetic alleles for identifying regions or specific amino acid residues critical for function or regulation of DNA repair pathways.