Detection of HBsAg in Coagulation Factor IX Concentrates

HBsAg was detected in two commercial clotting factor concentrates: Proplex (Hyland) and Konyne (Cutter). HBsAg was positive by RIA in samples of Proplex but not Konyne. Immune-electron microscopy, however, demonstrated clumped small spheres of HBsAg in both preparations, and lamellar-type strands were seen in several preparations.