Quantification of immunofluorescence on individual erythrocytes coated with varying amounts of antigen.

Abstract

Quantification of the parameters in an antigen—antibody fluorescent reaction in which it was possible to vary the amount of the antigen, was carried out in a model system. Formalinized erythrocytes were coated with different amounts of 131I-labelled human IgM. The cells were then exposed to fluorescein-conjugated antiserum to human IgM. The fluorescence intensity of individual cells was measured with a microspectrofluorimeter. As the cells were coated with varying amounts of protein it was possible to investigate the relationship between the quantity of protein antigen and the intensity of fluorescence.