[Detection of antibodies against the virus causing viral gastroenteritis in swine using the modified autoradiography...

A modified method for autoradiographic determination of antibodies to the virus of transmissible gastroenteritis of swine was developed. It is based on the actual reaction between antigen bound in cells of the infected cell cultures and antibodies in tested sera, which is visualized, by help of rabbit antibodies marked 125J (125J RaSw IgG antibody) to porcine IgG, on a sensitive radiograph and evaluated on the basis of darkening at the point of positive immunological reaction. Specificity of the test and mutual comparability and reproducibility of the results were confirmed by examining the known positive and negative sera and by comparison with the results of the virus-neutralisation test. Out of the 36 examined porcine blood sera the antibodies were proved autoradiographically only in the samples positive also by virus-neutralisation. In experimentally infected pigs, the same dynamics of antibody production was recorded by the two tests. They were, however, demonstrated autoradiographically already by the two tests. They were, however, demonstrated autoradiographically already the eighth day after infection, while by virus neutralisation test as late as 14th day. Their level increased gradually until 35th day after infection.