Enzyme immunoassay for detection of Mycoplasma bovis antigens in bull semen and preputial washings

A capture enzyme immunoassay was developed for the detection of Mycoplasma bovis antigens in bull semen or preputial washings. IgG prepared from rabbits immunised with M bovis was passively adsorped to 96-well polystyrene plates. This antibody captured M bovis antigens which were then detected by using an IgG preparation from an immunised cow and murine monoclonal antibody to the bovine L-chain conjugated with horseradish peroxidase. The sensitivity of the assay was approximately 200 colour changing units (ccu)/ml and the specificity was excellent in that other species of mycoplasma, ureaplasma or acholeplasma did not react. A blind study of bull semen experimentally contaminated with M bovis detected all specimens with more than 200 ccu/ml.