EVALUATION OF THE MICRONUCLEUS TEST IN-VITRO USING CHINESE-HAMSTER CELLS - RESULTS OF 4 CHEMICALS WEAKLY POSITIVE IN THE IN-VIVO MICRONUCLEUS TEST

A rapid and simple procedure for the micronucleus test (MNT) in vitro using Chinese hamster ovary (CHO) cells was established in our laborat ory. The assay is intended to quickly screen chromosomal aberrations i n vitro within the framework of indvstrial genotoxicity studies. To te st the sensitivity of the assay in the experiments described here, Fou r substances, classified as noncarcinogens but reported as weak induce rs of micronuclei (MN) in bone-marrow cells of mice, were evaluated in the MNT in vitro. Of the four compounds, ascorbic acid, phenol, and 2 ,6-diaminotoluene proved to be genotoxic in the MNT in vitro. Titanium dioxide, which could not be dissolved in the culture medium, did not induce MN. The MNT in vitro proved to be quick and relatively simple a nd to yield highly reproducible results when resting the four chemical s. (C) 1995 Wiley Liss, inc.