Utilization and stability of vitamins in serum-containing and serum-free media in CHO cell culture.

The concentrations of four vitamins, ascorbic acid, nicotinamide, choline and thiamine were evaluated in the culture supernatant of Chinese hamster ovary (CHO) cells. The media used were alpha-modified Eagle's minimum essential medium (MEM-alpha) supplemented with 10% fetal calf serum, and a 1:1 mixture of Ham's F12 and Dulbecco's modified Eagle's medium (DME/F12), containing neither serum nor protein. The reference experiment without cells revealed instability of ascorbic acid and thiamine. Moreover, a significant amount of each vitamin decreased in the culture supernatant. The possibility of growth limitation by vitamin depletion is strongly suggested.