NUTRITION OF ANIMAL CELLS IN TISSUE CULTURE: IX. SYNTHETIC MEDIUM No. 703

Abstract

Previous reports from this laboratory described a synthetic medium, solution 199, that contained 60 ingredients and supported cell life for an average period of four to five weeks. The assays were carried out in roller tubes in which chick embryo mesenchyme tissues were cultivated directly on the glass. More recently, the synthetic media have been improved very considerably, and Earle's replicate culture assay procedures have been adapted for use in testing them. By means of these techniques, it has been possible to make accurate quantitative experiments with new synthetic solutions some of which are capable of yielding, in one week, five- and sixfold increases in the population of replicate cultures prepared from washed suspensions of Earle's L strain mouse cells. This was acommplished by omitting the purines and pyrimidines from solution 199, by adding greatly increased levels of cysteine, ascorbic acid, and glutathione, and by the addition of certain purified coenzymes. In solution 703, which is described in detail, cultures of L strain cells have been maintained in a healthy, active state for over five months, with renewal of the medium twice a week.