Serological and biochemical analysis of the PlA1 alloantigen of human platelets

Abstract
A solid phase platelet antibody assay has been developed which rapidly and sensitively detects PlA1 antibodies. The three‐step assay is performed by: (1) adhering platelets to the wells of a microtitre plate, (2) incubating the platelets with test serum, and (3) adding radiolabelled Staphylococcal protein A which binds to the Fc domain of IgG antibodies. Immune reactions are detected by overnight autoradiography.Characterization of the PlA1 antigen was performed by using PlA1 antisera in immune precipitation assays. A 90 000 dalton molecular weight species was precipitated from PlA1 positive human and dog platelets.