DNA Polymerase Inhibition Assay (PIA) for the Detection of DrugDNA Interactions

The authors have devised a simple method for the detection of drug–DNA interaction and sequence selectivity in vitro (1 ).The method is based on the inhibition or termination of bacterial DNA polymerase(s) when it encounters modified DNA sequences. The DNA polymerase inhibition assay (PIA) has been successfully employed to study a variety of DNA binding and bonding agents. The method was initially validated for the detection of adducts formed by sequence-selective alkylators such as adozelesm and duocarmycm A (1 ,2 ). Subsequently, the method was modified to permit detection of nonbonding intercalators and nonintercalative binding agents, such as netropsin (unpublished results). This method is relatively safe for the user, as it employs less radioisotope than is required for the detection of alkylation products by conventional postlabeling or Maxam and Gilbert chemical cleavage techniques.