Abstract
When Walker carcinosarcoma 256 cells were grown under clonal growth techniques, 50-100% plating efficiency was noted in a medium containing whole bovine serum. When dialyzed serum was used in the medium, few or no colonies were formed. Addition of pyruvate, [alpha]-ketoglutarate, and/or oxalacetate to the substrate resulted in plating efficiencies of 90-100%. Activity of these 3 metabolites was the same irrespective of addition of individual compounds or combinations thereof. Other citric acid cycle acids and metabolites tested failed to promote survival and growth of isolated Walker cells.