Immunodiffusion test in avian encephalomyelitis. I. Standardization of procedure and detection of antigen in infected chickens and embryos.

The double immunodiffusion technique was applied to avian encephalomyelitis virus (AEV). Agar gel medium containing such a high concentration of NaCl as 15% was more preferable for highly diluted quantities of reactants than any other NaCl-containing medium. A single precipitin line appeared on the 1st to 7th days of diffusion at room temperature. The specificity of reaction between AEV antigen and homologous immune chicken serum has been demonstrated by no cross reaction between heterologous viruses and specific absorption by homologous virus. The antigen was produced in the brain, viscera, eyeball, whole body and yolk sac of chick embryos inoculated via yolk sac, as well as in the thigh muscles of chicks subcutaneously inoculated at 2 days of age. Antigenicity was detectable in 50% emulsion of these organs with a virus titer more than 10(5.0) per 0.1 g of tissue weight.