Nutrition of Animal Cells in Tissue Culture: Vii. Use of Replicate Cell Cultures in the Evaluation of Synthetic Media

The replicate culture assay procedures of Earle and his associates have been adapted for use in evaluating the effectiveness of synthetic media. For this purpose, use has also been made of Earle's L strain mouse cells. Washed and continuously stirred suspensions of these or similar strains of cells may be dispensed, with reasonable assurance of uniformity, into a series of replicate cultures, the number depending on the volume of the suspension and the capacity and effectiveness of the stirring and dispensing unit. For use with synthetic media, the original procedures for the preparation and care of the replicate cultures and for their subsequent treatment for the counting of isolated, stained nuclei have been modified considerably. This paper describes the procedures that were finally adopted and also describes a relatively simple screening procedure in which washed cell suspensions may be used to advantage in making preliminary assays of synthetic media and in testing the relative toxicity or growth stimulating effects of substances added to, or derived from, natural media.