title: Immunodiffusion test antigen from bluetongue virus-infected newborn mouse brains.
abstract: Three methods of extracting bluetongue virus (BTV)-infected newborn mouse brains to prepare immunodiffusion (ID) test antigen were used. The most readily readable and reproducible results were obtained with fluorocarbon-extracted brains homogenized in 8.5% sucrose. Mouse brain- and reference cell culture-derived antigens gave a line of identity with anti-BTV serum. Extracts of noninfected brains were nonreactive. ID tests on field-collected bovine sera, comparing the two types of antigen, resulted in only 73% agreement due to a greater sensitivity of cell culture-derived antigen. A 70.5% agreement resulted when comparing mouse brain-derived antigen in ID tests with complement fixation tests, the latter being least sensitive. ID test results with sera from experimental sheep gave 95.9% agreement between cell culture- and mouse brain-derived antigens. Between ID, which detects antibody to the BTV common or group antigen, and virus neutralization, which detects type-specific antibody, the agreement was 71.4% with postchallenge sera. Data from pre- and postinjection sera, however, indicate the possible activity in Texas of viruses other than International BTV Types 10, 11, 13, and 17.
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis*; D000956:Antigens, Viral; D001819:Bluetongue / Q000276:immunology; D001820:Bluetongue virus / Q000276:immunology*; D001921:Brain / Q000276:immunology; D003168:Complement Fixation Tests; D005779:Immunodiffusion; D051379:Mice; D009500:Neutralization Tests; D012087:Reoviridae / Q000276:immunology*; D012756:Sheep
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral