Nutritional requirements of primary cultures a neglected problem of modern biology

The growth and metabolism of cultured mammalian cells are markedly affected by the pH variation in ordinary hicarbonate-buffered media (pH 8.0 to 6.9). Those pH swings can be reduced and the pH of the culture can be stabilized as desired in the range pH 6.4 to 8.3 by appropriate combinations of two or three organic buffers, each at 10 to 15 millimolar, in conjunction with phosphate and bicarbonate. The initial alkalinization in sparse cultures is then minimized, and the metabolic acidificatiotn in 24 hours is usually less than 0.4 pH unit except in heavy cultutres.