Development of an Indirect ELISA Based on the Recombinant outer Membrane Protein (Omp) P2 for Detecting Antibodies against Haemophilus parasuis

This experiment was conducted to detect the antibody of Haemophilus parasuis(HPS)based on the recombinant outer membrane protein(Omp) P2 through indirect ELISA.An indirect ELISA was developed and optimized with the purified recombinant HPS Omp P2 as coating antigen.The optimal conditions of ELISA were determined as follows.The microplate was coated with 150 ng of the recombinant P2 protein per well,and then blocked overnight at 4℃.The serum samples were diluted at 1∶ 80 and goat anti-pig HRP-IgG was diluted at 1∶ 4 000.The cutoff values at 450 nm of the negative or the positive sera were 0.231 or 0.280.The coincidence rate between the ELISA and Biovet HPS antibody test kit was determined as 88.9%.The results indicated that the indirect ELISA was specific and could be used for detecting anti-HPS antibodies.