EN
The aim of the present paper was to find out by in vitro chromosomal aberration test using human lymphocytes whether cysteine has anticlastogenic properties towards a well-known mutagen - mechlorethamine. The lymphocytes tested were obtained from three healthy donors. Two doses of cysteine (1.0 and 2.0 μg/ml) and three doses of mechlorethamine (0.1,0.2 and 0.3 μg m⁻¹) were tested. It was found that cysteine had anticlastogenic properties and that it reduced the number of metaphases with chromosomal aberrations induced by mechlorethamine.