Twenty eight American mink × Chinese hamster somatic cell hybrids were analysed for the expression of mink enzymes and for mink chromosomes. The results of this analysis made it possible to assign the genes for phosphoglucomutase-1 and phosphogluconate dehydrogenase to chromosome 2, those for lactate dehydrogenase A and glucose phosphate isomerase to chromosome 7, and those for lactate dehydrogenase B and triosephosphate isomerase to chromosome 9