The fluorescein-antifluorescein quenching system as a model for assaying changes in antibody function

A rapid, simple and inexpensive procedure is presented for utilizing the fluorescein-antifluorescein quenching reaction as a model system to monitor and evaluate changes in antibody function brought about by conjugation and modification procedures. Experiments showing 1) the gradual loss of antigen-binding activity during dinitrophenylation, 2) the partial loss and subsequent recovery of activity during the reversible blocking of amino groups by citraconylation and 3) the quantitative release of bound fluorescein during guanidine denaturation were performed to demonstrate the versatility of the model.