RESUMEN
The tissue culture of human colonic carcinoma with and without feeder layers of confluent C3H 10T1/2 mouse fibroblast was compared. In a series of 27 different tumor specimens, 21 long-term cultures (6 mos. or more) were obtained by utilizing feeder layers. Only 3 long-term cultures were obtained from the same set of specimens when feeder layers were not employed. Several of the long-term cultures were established as cell lines weaned from fibroblast feeder layers. These lines could be classified into 3 groups based upon their expression of several biological properties including tumorigenicity in nude mice, degree of differentiation of the tumors growing in nude mice, growth in semisolid medium, morphology in vitro and production of carcinoembryonic antigen in vitro.