Preparation of Newcastle disease virus antigen for use in HI tests
Antigen is prepared by inoculating embryonated eggs with a sample of Newcastle disease virus and harvesting the allantoic fluid four days later. Part of the first batch of I-2 Newcastle disease vaccine prepared from the I-2 working seed can be set aside for storage as antigen. A volume of 50 mL to 100 mL is adequate for a large number of tests. Centrifuge the sample at 1 200 g to clarify and remove any contaminating red blood cells. Store the antigen in one mL aliquots at -20°C.
See Sections 6 and 9.