Purification and concentration of influenza inactivated viruses by continuous-flow zonal centrifugation

A mathod is described for the purification, on an industrial scale, of influenza viruses grown in allantoic cavity of embryonated eggs. The mehtod consists of combining continuous-flow centrifugation with zonal centrifugation in a sucrose (36.6 per cent-52.5 per cent w/v) density gradient. The sample flow rate is approximately 3.7 litres/h and the volumes treated vary between 3 and 33 litres of allantoic fluid. Both the recovery of the virus and the degree of concentration and purification result satisfactory.