McCoy’s 5A Medium was first described by Neuman and McCoy in two publications (1958 and 1959) in growing Walker Carcinosarcoma 256 cells and Novikoff hepatoma cells. The constituents of the original basal medium are as follows: all amino acids including hydroxyproline, thiamine, riboflavin, aminobenzoic acid, pyridoxine, pyridoxal, nicotinic acid, nicotinamide, calcium panthothenate, biotin, folic acid, vitamin B12, choline chloride, inositol, ascorbic acid, glutathione, salts, glucose, phenol red, penicillin, and dialyzed serum. Commercial formulations of McCoy’s 5A may contain additional components or supplements.