Specificity of the anti-p36 MAbs as determined by Western immunoblotting. The anti-p36 MAbs were tested for their reactivity to three reference M. hyopneumoniae strains and other mycoplasma species most commonly found in pigs. Lane 1, M. hyopneumoniae strain ATCC 25934; lane 2, M. hyopneumoniae strain J; lane 3, M. hyopneumoniae strain ATCC 25095; lane 4, M. arginini; lane 5, M. flocculare; lane 6, M. hyorhinis; lane 7, A. laidlawii; lane 8, M. hyosynoviae; lane M, low-molecular-weight markers.