The localization of antilymphosarcoma antibodies in the Murphy lymphosarcoma of the rat.

INTRODUCTION In a previous report, we have shown that antisera prepared against a mouse tumor (the Wagner osteogenic sarcoma) contained antibodies capable of localizing in vivo in the mouse tumor, while antisera prepared against normal mouse organs did not. We had already shown that antisera prepared against normal rat (2,4, 7, 9,10) and mouse tissues (5) contained antibodies capable of localizing in these tissues in vivo. The present work shows that antisera prepared against the Murphy lymphosarcoma of rats con tained antibodies which localized in this tumor, and that such antibodies were absent in other antitissue sera. The presence of localizing anti bodies was demonstrated as follows: The globulin fractions of control sera and antisera were iodinated with iodine containing radio-iodine (I131), and the antibodies were purified by treating these radio-iodinated globulin fractions with lympho sarcoma sediment and subsequently eluting the adsorbed antibody (8). These purified antibodies were then injected into rats bearing the tumor, and the tumor and other tissues were assayed 24 hours later for their content of radioactivity. Increased localization of radioactivity in tumor from antitumor sera showed the presence of localizing anti bodies.