The effect of carcinogens on the nuclear size of HeLa cells

The size of HeLa S-3 cell nuclei was measured after 1--3 days in culture. After exposure to carcinogens, nuclear size increased and the frequency distribution pattern of nuclear size changed. The optimal conditions for these changes were the use of concentrations of chemicals which had a low order of cytotoxicity and the measurement of nuclear size 48 h after pulse treatment of the cells for 30--60 min. These effects were not seen with non-carcinogens. The results obtained suggest that changes in nuclear size may be an index of chemical carcinogenicity.