Use of yolk sac route of inoculation for titration of lentogenic strains of NDV.
D000818:Animals; D002642:Chick Embryo / Q000276:immunology*; D005321:Extraembryonic Membranes / Q000276:immunology; D006386:Hemagglutination Tests; D009500:Neutralization Tests; D009522:Newcastle disease virus / Q000276:immunology*