A new assay of deoxyriboucleases using as a substrate radioactively labelled DNA bound either directly or through anti-DNA antibodies to plastic depression plates.

A simple and accurate method for the detection of Deoxyribonucleases is described. The DNA substrate (3H-labeled) is bound to DNA-binding sites in the "wells" of plastic depression plates either directly of via anti-DNA antibodies. Following incubation with the appropriate enzyme, the radioactivity released from the wells or left bound to the wells is determined. The method is suitable for enzymes which attack native DNA, single stranded DNA and modified DNA (e.g., u.v.-irradiated) as substrates.