An Isotopic Antiglobulin Technique for Measuring Antibodies to Cell-Surface Antigens

The isotopic antiglobulin technique of Harder and McKhann has been modified and the sensitivity increased. The method was shown to be immunologically specific and able to detect isoantibodies after first-set skin grafts which were not detectable by the cytotoxicity technique. Antibodies to different H-2 antigens were detected in the sera of several inbred mouse strains following immunization with spleen cells or skin grafts. In several of these antisera, antibodies were detected at serum dilutions which gave negative results by the cytotoxicity technique. Several variables of the technique were investigated and the number of washing procedures after each incubation was found to have the greatest effect on increasing the sensitivity of the test.