The Use of the Preparative Ultracentrifuge to Detect Primary Interactions between I131-Labeled Antigen and Antibody

Abstract

Summary The different sedimentation characteristies of free I131-labeled antigen (I*antigen) and I*-antigen-antibody complexes in the preparative ultracentrifuge have been used as the basis for a test to detect and measure the primary interaction between antigen and antibody. When serial dilutions of 10 different rabbit anti-bovine serum albumin sera were studied the results obtained with the ultracentrifuge method correlated well with data obtained by the ammonium sulfate technique. The broad applicability of the ultracentrifuge method is illustrated by studies of the use of the method to detect antibody against bovine γ-globulin, and antigen difficult to study by most other primary binding techniques.