Rapid clonal growth and serial passage of human diploid fibroblasts in a lipid-enriched synthetic medium supplemented with epidermal growth factor, insulin, and dexamethasone.

A serum-free, hormone-supplemented medium, enriched with a mixture of lipids, has been developed that supports rapid clonal growth of human diploid fetal lung fibroblasts (Flow 2000, WI-38, MRC-5, and IMR-90) and of low-passage human foreskin fibroblasts. The medium, which contains less than 1 microgram of total protein per ml, also supports serial passage of Flow 2000 cells under totally serum-free conditions. It provides lipid at a total of 10 micrograms/ml as a liposome prepared from a mixture of soybean lecithin, cholesterol, sphingomyelin, vitamin E, and vitamin E acetate. The soybean lecithin, which contains a variety of naturally occurring phospholipids, can be replaced with a mixture of highly purified phospholipids. Except for possible contaminants in the substances used in its preparation, the serum-free medium is fully defined chemically. It consists of an optimized basal nutrient medium, MCDB 110, supplemented with insulin, epidermal growth factor, dexamethasone, prostaglandins E1 and F2 alpha, phosphoenolpyruvate, dithiothreitol, glutathione, and the lipids listed above.