Division 3 Inoculation and incubation of eggs

To isolate mammalian influenza viruses in 9- to 11-day-old embryonated fowls' eggs it is usual practice to inoculate each egg via the allantoic cavity and into the amniotic cavity. However, when testing pigs in contact with AI viruses, when virus has had little opportunity to adapt, allantoic cavity inoculation is probably sufficient.

Similarly, 35 ^oC is usually recommended for the incubation temperature for isolation of mammalian influenza A viruses, but again for viruses poorly adapted to pigs, 37 ^oC is not be detrimental to virus isolation.