Cytotoxicity of Heterologous Immune Chicken Serum to Normal and Neoplastic Mouse Tissues in Culture

New Hampshire Red cockerels were immunized against the Sarcoma 180 mouse tumor and against tissues of normal mice of its BALB/c host. Plasmas and serums from immunized and nonimmunized chickens were used in tissue cultures of the tumor and of embryonic mouse tissues. Antibodies against the tumors showed cytotoxic effects on tumor cells even after absorption with normal mouse antigens, but did not affect embryonic cells. Similar effects were not shown by antibodies against normal mouse tissues.