“…In the present study, we needed to extend this approach to a series of aromatic amines that require metabolic activation prior to exhibiting genotoxicity in vitro. A useful starting point for this study is the work of Asquith et al (1985) where liver $9 fractions were used with the promutagen benzidine to study CA effects in cultured lymphocytes. Thus, in the present investigation, in addition to benzidine, 4-aminobiphenyl, 4-amino-4'-nitrobiphenyl, 4-aminostilbene, 4,4'diaminostilbene and 4-amino-4'-nitrostilbene were examined for CA in mouse lymphocyte cultures following direct in vitro exposure of the amines to the cultures as well as in lymphocyte cultures prepared from mice subsequent to the i.p.…”