Strain specific antibodies revealed by immunoabsorption studies with avian infectious bronchitis virus.

Rabbit antisera prepared against the Massachusetts 41 (M41) strain of avian infectious bronchitis virus (IBV) and absorbed with chick embryo immunoabsorbent produced multiple precipitin lines in immunodouble-diffusion (IDD) tests with homologous or heterologous strains of virus. These precipitin lines were all removed by absorption with concentrated M41 virus preparations, but repeated absorption with concentrated, purified preparations of IBV strains: T, Holte, Connecticut, Beaudette or H120 failed to remove all precipitin lines produced to M41 virus, although all those to the heterologous viruses were removed. The remaining line(s) produced with M41 virus by sera absorbed with different heterologous viruses showed identity in IDD tests and was associated with the surface projections of the virus.