Plasma Derivatives in Tissue Cultures Intended for Growth of Poliomyelitis Viruses.

Abstract

Synthetic media, such as mixture 199, will support only moderate growth of epithelial cells (monkey kidney) in tissue culture. The addition of serum enhances growth in this system. Since the use of specific plasma fractions may be preferable, in bulk growth of poliomyelitis virus, this aspect was investigated both as regards degree of tissue growth and the virus yields which could then be obtained. Growth enhancing factors were found in both fraction IV and V (Cohn) of human plasma. The former proved to be heat-labile, but the latter, as expected, could be heated at 56[degree] C for 8 hours without marked loss of activity. Titrations of these fractions against horse and human serum showed that the active substances were concentrated in the former according to the growth enhancing value of the latter. Bovine plasma fractions were equally as active as the human ones. Tissue grown out in medium consisting of mixture 199, plus horse-serum and/or human fraction IV, was infected with Type I poliomyelitis virus. Yields of the latter were higher in both series containing additives than in the controls grown in mixture 199 alone. More virus, however, was obtained from the tissues grown with added human fraction IV than from those cultured in the presence of horse serum. This may have merely reflected the number of susceptible cells present in the respective preparations since growth was heavier in the flasks containing human plasma derivative.