[Micronucleus test in cultured cells--preliminary study].

In mutagenicity and carcinogenicity assays using micronucleus test, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 50 mg/kg or benzo(a)pyrene (BaP), 100 mg/kg did not increase the incidence of micronuclei in polychromatic erythrocytes in bone marrow of mice. MNNG, 0.1 microgram/ml could induce a significant increase of micronuclei with dose response in cultured V79 cells. In another experiment of Syrian hamster embryo cells, the induction of micronuclei was seen after benzo(a)pyrene, 0.1 microgram/ml treatment. The combined use of micronucleus test in vivo and in vitro can increase the sensitivity and reduce the false negativity obtained in vivo micronucleus test.