Purification of infectious pancreatic necrosis virus by anion exchange chromatography increases the specific infectivity

Abstract

An improved method for the isolation and purification of infectious pancreatic necrosis virus (IPNV) is described. Virions released into the clarified growth medium are adsorbed to an anion exchange resin of diethylaminoethyl cellulose at pH 8.1. IPNV together with the likewise released and accumulated excess pool of the precursor to the major capsid protein, ICP62, are eluted at a salt concentration between 100 and 125 mM NaCl. The bovine serum albumin content of the growth medium supplement also elutes close to this position. Upon one step of combined sucrose- and CsCl-gradient centrifugation the recovered viruses display lower levels of aggregation, higher specific nucleic acid contents and an approximately 350% higher specific infectivity as compared with pools of viruses processed in parallel and isolated according to the established method relying on precipitation with poly(ethylene glycol).