Establishment of two parental cell lines and three clonal cell strains from rat colonic carcinoma

Two epithelial cell lines were established from separate pools of cells that were harvested by a sequential proteolytic treatment of a single specimen of rat transplantable colonic carcinoma. The cells were small (10-micrometer diameter) and cuboidal and displayed desmosomes and light junctions. Both cell lines grew rapidly with population-doubling times of 20 to 22 hr, were near diploid in chromosome number, contained A-2 and B-7 marker chromosomes, and were tumorigenic in rats. Each was distinguishable from the other by the shape of its cell clusters in monolayer culture, its serum requirement for growth, its modal chromosome number, and its karyotypic alterations. Undifferentiated cells, cystic cells, and vacuolated cells, but not mature mucous cells, were observed in monolayer cultures. Clonal cell strains mimic the morphological and growth properties of their respective parental cell line but display unique karyotypic alterations in addition to the A-2 and B-7 marker chromosomes.