Comparison between recombinant and platelet-derived glycoprotein (GP)Ib for human platelet antigen (HPA)-2 antibody detection.

(A) An inert negative control serum and five different sera containing anti-HPA-2b tested against the Thr-145 and Met-145 forms of recombinant GPIbα by enzyme-linked immunoabsorbent assay. (B) The same sera tested against platelet-derived GPIbα by monoclonal antibody-specific immobilization of platelet antigens.