Establishment of Dc-ELISA. (A) Distribution of inhibition values of 20 negative and 20 positive serum samples by Dc-ELISA. A cut-off value was set as 32% (mean + 2SD). Positive sera had PI values exceeding 32% and negative sera had PI values less than 32%. (B) Inhibition of binding of P48 protein-specific mAb 10E binding by antisera against various pathogenic species. Lanes 1-10 respectively are: BADV3, BVDV, BPIV3, BRSV positive control serum, Rabbit hyperimmune antisera against M. bovirhinis, M. arginine and M. agalactiae, rabbit negative serum, bovine negative M. bovis serum, bovine M. bovis positive serum. Only the M. bovis positive serum had clear inhibition of mAb binding. The Error bars indicate the standard deviations from three-well replications for each serum sample.