Serum Action on Radiation Response in Tissue Culture

This study explores the action of serum in the radiation response of strain NCTC 2071 cells cultured in a medium free of serum or protein through more than 294 subculture generations for over 6 years. Since it is difficult, if not impossible, to wash serum completely from cells, even with multiple saline rinses, cells of this strain were ideal for this study. Cells in agitated fluid- suspension cultures on the Brunswick shaker for 28 days were used. It was shown that serum modified the radiation response by speeding recovery of the irradiated cultures when serum was added either before or immediately after irradiation; such cells began to recover at 10 days after irradiation. Cells irradiated in medium NCTC 109 without serum, however, usually did not resume growth, or if they did, it was only after 28 days. The mechanism of this action of the serum is discussed. (auth)