Concentration and purification of influenza virus from allantoic fluid

A simple procedure which enables the concentration and purification of influenza virus, using an angular rotor, is described. Virus is concentrated over a sucrose step gradient. The same gradients are reused and volumes up to 4 liters are concentrated in 1 day. The concentrated virus is further purified by a simplified density-gradient technique. No host cell protein is detectable in the final product. The technique offers a broad application potential for concentrating and purifying other viruses.