Procedures for the haemagglutination and the haemagglutination inhibition tests for avian infectious bronchitis virus

Abstract

Various aspects of production, storage and stability of the hemagglutination (HA) activity of infectious bronchitis virus (IBV) were studied. From results obtained, a standard procedure for production of IBV, HA and the HA and hemagglutination inhibition (HI) tests is suggested. The main points of the suggested procedure are: the virus should be concentrated but not purified; the virus should be treated with phospholipase C type 1 (PLC), at a final concentration of 1 unit/ml, for 2 h at 37.degree. C; the virus should be stored at 4 C after PLC treatment; and HA and HI test plates should be kept at 4.degree. C and read 45-60 min after addition of chicken red blood cells. Using the recommended standard procedure the HA and HI tests for IBV were as reproducible as the HA and HI tests for Newcastle disease virus.