[Effect of the nucleic acids from the ascitic fluid of Ehrlich's tumor on its transplantability]

The effect of nucleic acids isolated from ascitic fluid of Ehrlich tumor and Zaidela's hepatoma on the survival rate of C3Ha mice inoculated with Ehrlich tumor cells was studied. While nucleic acid preparations suppressed the cytotoxicity of immune lymphocytes in vitro, they failed to increase frequency of tumor inoculation in vivo. The addition of nucleic acid preparation to tumor cells mixed with syngeneic lymphocytes did not block immune defense against tumor growth either. The differences in the effects of nucleic acid preparations in vivo and in vitro are discussed.