Premixed Powders for Protein-Free Cell Culture Media: A Quantitative Evaluation

Summary

Chemically defined media prepared from ball-milled premixed powders were reconstituted with water and quantitatively evaluated for their capacity to support proliferation of cell strains in the absence of serum, protein, or protein hydrolysates. Powdered media at the time of this study were available commercially only from General Biochemicals (GBI). These were compared with liquid media of the same formulations prepared in the Tissue Culture Section, National Cancer Institute (NCI). The first two studies evaluated two media, NCTC 134 and the less complex medium NCTC 127. In later experiments NCTC 135 was tested. The cell strains used were derived from three mammalian species: NCTC 2071 (clone 929-L, mouse), NCTC 3075 (human skin), and NCTC 3526 (monkey kidney). In the GBI powdered media, proliferation rates were consistently lower than in the NCI liquid medium. Although satisfactory cell growth was obtained with the powdered media preparations at high inoculum levels, the growth rates at low inoculum levels were lower than in the NCI liquid media. Furthermore, the growth potential of the cells was reduced with prolonged culture in the powdered media preparations. Inadequacies existed in the powdered media as prepared and used without serum or protein supplements. These inadequacies suggest that some factor(s) in the ball-milling reduced the growth-promoting quality of the media.