A PLANT-EXTRACT WHICH ENHANCES THE PLATING EFFICIENCY OF LYMPHOID-CELL LINES AND ENHANCES THE SURVIVAL OF NORMAL LYMPHOID-CELLS IN-VITRO

A water soluble extract from the bark of the Samoan medicinal plant Al phitonia zizyphoides A. Gray (Rhamnaceae), enhances the plating effici ency in vitro of lymphoid cell lines as well as the survival of bone m arrow cells and normal T and B lymphocytes. Furthermore, the inclusion of bark-extract into culture media enhances the cloning efficiency of a T-hybridoma cell line by more than 30 times at otherwise unsuitably low serum concentrations, but does not completely substitute for seru m. The enhanced growth of a B-cell hybridoma is also paralleled by an increased production of monoclonal antibodies in cultures containing l ow cell densities.