Improved conditions for murine epidermal cell culture.

An improved method for cultivating newborn mouse epidermal cells has been developed that increases the longevity, epithelial nature and efficiency of cell-line establishment. The use of Super Medium, an enriched Waymouth's formulation, increased proliferation for long periods of time, as did incubation at 31 degrees C rather than 37 degrees C. The fetal bovine serum requirement was found to be reduced at the lower temperature. An increase in labeling indices was seen when epidermal growth factor (EGF) or the cyclic nucleotides were added and the presence of EGF receptors was determined. Of the prostaglandins (PG) examined, PGE1 and PGE2 produced the greatest increase in DNA synthesis. The PG precursors, arachidonic and 8,11,14-eicosatrienoic acid, were also greatly stimulatory. The use of a lethally irradiated 3T3 feeder layer at 31 degrees C proved superior in maintenance of an epithelial morphology. Subculturable cell lines were established much more readily and reproducibly in carcinogen-treated cultures grown under the improved conditions.