An avidin-biotin enhanced dot-immunobinding assay for the detection of Mycoplasma gallisepticum and M. synoviae serum antibodies in chickens

A dot-immunobinding assay was enhanced by the incorporation of avidin and biotin reagents into the test system (DAB assay). This assay was used to detect serum antibodies to Mycoplasma gallisepticum (NG) and M. synoviae (MS) from chickens. Serum samples were tested by rapid serum plate (RSP), haemagglutination-inhibition (HI), and DAB assay methods. The DAB assay was at least 20 times more sensitive in detecting antibodies for MS and at least 75 times more sensitive in detecting antibodies for MG than the HI test. The DAB assay was as specific as the HI test. The DAB assay was also more sensitive and specific than the RSP test. Some cross-reactions occurred when low dilutions of high-titre sera were used in the DAB assay. Parameters for determing negative, suspicious, and positive samples were established. The DAB assay for MG and MS may have several applications, including use as a screening test and a confirmatory test.