ELISA detection of PGN632 binding to immobilized PS. Antibody was added to ELISA plates coated with various phospholipids. Serial ten-fold dilutions of the antibodies were prepared. Plates were developed with HRP-labeled anti-human IgG followed by O-phenylenediamine dihydrochloride and the absorbance read at 490nm. PS, phosphatidylserine; CL, cardiolipin; PI, phosphatidylinositol; PA, phosphatidic acid; PG, phosphatidylglycerol; PC, phosphatidylcholine; PE, phosphatidylethanolamine; SM, sphingomyelin. Points; means of triplicate determinations.