Separation of human plasma factor IX from HTLV-I or HIV by immunoaffinity chromatography using conformation-specific antibodies

Immunoaffinity chromatography using conformation-specific antibodies yields pure factor IX from human plasma in a single rapid, facile purification step. We evaluated this technique to determine whether factor IX can be separated from human T cell leukemia virus-I (HTLV-I) and human immunodeficiency virus (HIV) in plasma supplemented with these viruses. Viral content was determined with an enzyme-linked immunosorbent (ELISA) assay sensitive to 50 ng viral protein. Both HTLV- I and HIV coeluted with unbound protein. Neither HTLV-I nor HIV was detected in purified factor IX. We conclude that, to the limits of detection, factor IX purified by this method is free of viral contamination.