Standardization of the human peripheral lymphocyte micronucleus test for the quantification of genotoxic exposure.

There is a paucity of in vitro tests to determine potential genotoxicity in human beings. In response to this need, a modified micro culture system was developed in order to study micronuclei production in human peripheral blood lymphocytes. Phytohemagglutinin (PHA) was added to peripheral blood lymphocytes exposed to increasing doses of gamma radiation. Results show that either PHA or radiation alone induces micronuclei production above background levels. However, PBML exposed to gamma radiation followed by incubation with PHA do produce micronuclei. A standardized assay measuring micronuclei, gama interferon, and DNA production, and an interpretation of the mechanism of induction of PBML micronuclei are presented.