Isolation of immunogenic neuraminidases of human influenza viruses by a combination of genetic and biochemical procedures.

Neuraminidases were purified from reassortant viruses (H6N1 and H6N2) containing the two antigenic subtypes (N1 and N2) found in human influenza viruses. Surface glycoproteins were solubilized with octylglucoside, and the neuraminidase was isolated by chromatography on DEAE-Sephadex. Neuraminidase isolated by this technique coeluted with viral lipids and spontaneously formed liposomes on dialysis. The purified neuraminidase was immunogenic in rabbits, producing a significant antibody response at dose levels as low as 1 microgram.