Triadic Labeling with I130, I131, and I133 for Controlled Determinations of Tumor-Localizing Antibodies23

Abstract

The triadic label technique was developed to provide a method for the comparison of pairs of tumor-localizing antibodies, over and above a variable background localization of nonspecific globulin. The technique involved the labeling of one antiserum globulin with one radioiodine isotope, the other with a second radioiodine isotope, and the control globulin with a third radioiodine isotope. To exemplify the use of the technique, I¹³⁰, I¹³¹, and I¹³³ were selected as triadic labels in two experiments. In one experiment the localizing properties of antihepatoma and antiliver antibodies were compared, over and above the background localization of normal globulin, in rats bearing hepatomas induced by N-2-fluorenylacetamide. In the second experiment the localizing properties of antihepatoma and antirat-plasma antibodies were compared, over and above the background localization of antirat-serum antiserum globulin, in rats bearing induced hepatomas and in normal rats.