An improved heat‐stable glutamine‐free chemically defined medium for growth of mammalian cells

A heat‐stable chemically defined medium, free of glutamine, is described for the growth of mammalian cells in suspension culture. The presence of L‐alanine in the defined medium permitted the omission of glutamine. A 22‐fold increase in the population of a substrain of mouse L cells was obtained (3.4 × 10 6 cells/ml) in six days with no medium replenishment during incubation. Maximum yields (27 × 10 6 cells/ml) were obtained by daily medium replacement and venting of cultures. Growth was also improved in a line of cat kidney cells and HeLa cells, and in another substrain of L cells.