Dual-colour FISH analysis to characterize a marker chromosome in cytochrome P450 2B1 recombinant V79 Chinese hamster cells

Recombinant V79 Chinese hamster cell lines have been constructed for the ex pression of useful functions, e.g. cytochromes P450, in order to study meta bolism-dependent toxicity. Recombinant cell lines are derived as single clo nes upon gene transfer and selection from the parental V79 cell line. It is of fundamental importance for a reliable application of the recombinant ce ll lines to show that the original biological characteristics of the parent al line are maintained. As part of these efforts, fluorescence in situ hybr idization with Chinese hamster chromosome-specific DNA libraries was perfor med in order to identify the origin of the chromosomes from which a marker chromosome present in the recombinant cell line V79MZr2B1 was derived, whic h could not be identified by standard cytogenetic techniques.