Leibovits's L-15 Media was formulated to support the growth and proliferation of several cells lines in CO2 free systems without a sodium bicarbonate supplement. Whereas most cell culture media is buffered by sodium bicarbonate, L-15 is buffered by its salts, free base amino acids and galactose, which is substitutes for glucose. The buffering qualities of these components eliminate the need for a sodium bicarbonate supplement and allow the media to be used under conditions free of gaseous exchange with the atmosphere.