Development of immunoglobulin class-specific enzyme-linked immunosorbent assays for measuring antibodies against avian rotavirus.

Immunoglobulin class-specific enzyme-linked immunosorbent assays were developed for detecting antibodies against avian rotavirus in serum, intestinal contents, and bile from experimentally infected specific-pathogen-free (SPF) chickens. Both indirect and antibody-capture (AbC) assays were developed based on monoclonal antibodies specific for chicken IgG, IgM, and IgA. Treatment of purified rotavirus with sodium thiocyanate before coating the plate improved the rotavirus-specific reading in the indirect assay. Use of Immunolon 2 plates facilitated attachment of monoclonal antibodies to the plate in the AbC assay. Addition of 5% powdered skim milk to the diluent buffer reduced nonspecific background readings. The indirect assay was superior for detecting rotavirus-specific IgG, whereas the AbC assay was better for detecting rotavirus-specific IgM and IgA. The presence of intestinal contents in the assay wells did not reduce the measurable titers of IgG, IgM, or IgA. These assays showed that SPF chickens produced systemic and mucosal antibodies against avian rotavirus.