LOCALIZATION OF GW-39 HUMAN TUMORS IN HAMSTERS BY AFFINITY-PURIFIED ANTIBODY TO CARCINOEMBRYONIC ANTIGEN

Abstract

With the paired labeled antibody technique, the in vivo localization of radioiodinated, affinity purified antibody to carcinoembryonic antigen (CEA) was studied in GW-39, a xenografted, CEA-producing [colonic] tumor model. When compared to the whole immunoglobulin G fraction, a 4-fold greater tumor accumulation of radioantibody was obtained with affinity purified specific CEA antibody. The degree of increased tumor localization of affinity purified antibody was similar to its improved immunoreactivity as observed in radioimmunoassay and binding to CEA immunoadsorbent. Affinity purified antibody cross reactive with CEA and colon carcinoma antigen III was as equally effective in tumor localization as specific CEA antibody prepared similarly. It appears that affinity purified CEA radioantibody will provide a superior tumor imaging agent for clinical use.