Hepatitis C-virus-asialoglycoproteiner

The following are claimed: (A) an isolated hepatitis C virus (HCV) a sialoglycoprotein (AG) selected from E1 and E2; (B) a method for purifying HCV AGs, which comprises (a) contacting a compsn. contg. HCV AGs with a mannose-binding protein, e.g. concanavalin A (ConA) or Galanthus nivalus agglutinin (GNA) and (b) isolating the portion of the compsn. which binds to the mannose-binding protein, e.g. by elution with mannose; (c) an assay kit for detecting the presence of HCV AGs, comprising (a) a solid support, (b) a mannose-binding protein, and (c) an antibody specific for the HCV AG, where one of the antibody and the mannose-binding protein is bound to the solid support; (D) a method for determining exposure to or infection by HCV, in which any HCV in a sample of body fluid is concd. by contact with a mannose-binding protein prior to assay; (E) a cell transformed with a vector for recombinant expression of a HCV AG, where the vector comprises a structural gene encoding a glycosoylation signal, a HCV AG, a regulatory sequence operable in the host cell and capable of regulating expressio fo the HCV AG, and a selectable marker, where the cell does not sialylate glycoproteins; and (F) a method for reducing or eliminatng the presence of HCV in plasma, serum or other biological liquids.