Culture medium for tissue culture techniques

In a serum-free, protein-free, culture medium composition for the propagation of animal tissue cells in tissue culture, the composition comprising a buffered aqueous solution of sugars, amino acids, mineral salts and vitamins, the improvement wherein the culture medium further comprises a growth-enhancing amount of a strongly basic anion-exchange resin obtained by reacting trimethylamine with a halomethylated polymer prepared by reacting chloromethyl methyl ether in the presence of a zinc chloride catalyst with beads of a copolymer of about 90 percent of styrene and 2 percent of divinylbenzene and a water-soluble lipid source selected from the group consisting of polysorbate 60 and polysorbate 80 in an amount of from about 0.001 to about 0.100 parts by volume of lipid source per 100 parts by volume of medium.