Egg bit technique vis-a-vis embryonated eggs for the infectivity assay of Newcastle Disease virus

摘要

Embryonated chicken eggs are commonly used for infectivity titration and serum neutralization tests of viruses belonging to the orthomyxo and paramyxo-viridae families. However, the cost of eggs and difficulties encountered in their acquisition, incubation space, etc. are the common constraints associated with this technique. Fazekas et al., (1958) stanclardised the use of the bits of chorio-allantoic attached to the egg shell for titrating the influenza virus. The method was easier, economic and afeasible alternative to the use of whole egg. Beard (1969) adapted this technique for titrating the Newcastle Disease virus (NDV). The present communication, reports the utility of egg bits for assessing the infectivity of few strains of NDV.