title: Development of the AG68L strain of Newcastle disease vaccine. (2) Stability testing of clone-purified virus.
abstract: The fifth passage of a selected small plaque of the original AG68L virus seed was back passaged in susceptible chickens and the virus recovered was compared with the original virus for any change in characteristics. The results showed that the chicken passaged virus had not altered from the cloned seed. The method is proposed as a way of determining genetic stability of cloned virus.
authors.affiliation: International Reference Laboratory for Newcastle Disease, Central Veterinary Laboratory, Weybridge, United Kingdom.
authors.forename: L J
authors.initials: LJ
authors.lastname: Borland
authors.forename: W H
authors.initials: WH
authors.lastname: Allan