Rat leukaemia cell line grown on a chemically defined medium

Leukaemia cells of C12/0 line, derived from Gross virus-induced W/Fu rat thymoma, have been successfully maintained in a completely synthetic, serum-free RPMI 1640 medium. The cells propagated as good as in serum-supplemented medium, though they could not grow from a low cell density. Cells adhered to the substratum and did not survive. This problem was overcome by use of silicone-coated substratum, or of microexudate from C12/0 cells adsorbed on the substratum. The cells underwent degeneration soon after they reached their maximum density. C12/0 cells released macromolecules might possibly have both growth-promoting and toxic effect on the cell itself.