In vitro morphological transformation of cryopreserved hamster embryo cells with tobacco tar

Cryopreserved primary cultures of Syrian golden hamster embryo cells were used as the source of target and feeder cells for in vitro bioassay of carcinogenesis. Since cultures that gave the best overall response in a preliminary test were used for the bioassay, in almost every case a range of responses was obtained. By the use of this of this bioassay system, the capacities of tobacco tar and its subfractions to induce morphological transformation were examined. Some fractions induced typical morphologically transformed colonies. A close correlation was observed between morphological transformation and bacterial mutagenesis.