A new technique in quantitative immunohematology: solid-phase kinetic enzyme-linked immunosorbent assay

A solid-phase kinetic enzyme-linked immunosorbent assay has been developed to measure binding of antibodies to purified or synthetic blood group antigens and tested in the Lewis blood group system. Chemically synthesized Lewis a antigen is used as the target for the binding of serum antibody in this sandwich-type assay. Kinetic, rather than endpoint, determinations are used to calculate the amount of specific antibody. Data are presented showing the assay to be quantitative, sensitive, and specific. It can separately quantitate the amount of IgG or IgM anti-Lewis a present in patient sera. The assay uses commercially available reagents and is semiautomated. Thus, it will be useful for studies in quantitative immunohematology as other blood group antigens become available in purified form.