Assays for determining lesion bypass efficiency and mutagenicity of site-specific DNA lesions in vivo.

DNA damage, if left unrepaired, may hinder translesion synthesis, leading to cytotoxicity, and instruct a DNA polymerase to incorporate an incorrect incipient base opposite the damage, leading to mutagenicity. This chapter describes technology used to measure quantitatively the degree to which a specific type of DNA damage impedes DNA replication. The technology also quantifies the mutation frequency and specificity of such damage after replication within cells. If cells with defined defects in DNA repair are used as hosts for replication, one can pinpoint the specific enzymes or pathways of repair that are operative on specific types of DNA damage.