Studies on The Serological Detection of Avian Encephalomyelitis Virus nfectious In chickens

Studies were carried out to determine the relat:tve merits of the agar-gel precipitin test (AGPT) and thepassive haemagglutination test (REAT) as compared with the embr-yo susceptibility test (EST) in the diagnosis of avian encephalomyelitis virus (liliV) infection in”:!j chickens. Experiments were first carried out to determinethe suitability of various antigen preparations and hyperimmune sera for the AGPT and the PEAT, the speoi-ficity of both reactions, and the effect of certain ~aPiables on the AGPT. In further experiments1 the prac-tical application of the AGPT and the PEAT was attempted on breeding flocks ’l,\”iijh and wi thout history of previous . In unvac~inated flocks, the EST was adapted p ar a Ll.e 1 with the other two tests.It was found that antigen extracts-prepared fromvarious tissues of infected ohick embryos prepared in phosphate buffered saline and partially purified andconcentrated by treatment with chloroform and ammoniumsulphate or polyethylene glycol (PEG) generally showed more antigenicity and gave higher titer of antiserum