Establishivient of Recombinant N Protein Based ELISA for Detection of Antibody Against Porcine Reproductive and Respiratory Syndrome Virus
Abstract: The recombinant plasmid pETN was transformed into E.coli BL21 (DE3) host cell and the expression product-recombinant nucleocapsid protein of PRRSV was obtained under the optimized condition of host cell cultivation and IPTG induction. Consequently, the expression product was purified by means of his-binding resin protein purification procedure. SDS-PAGE and Western-blot were used to detect the purification effect and the specificity of purified recombinant nucleocapsid protein of PRSSV. The purified N protein was used to coat 96-well plate, each step was optimized, such as coating concentration of recombinant nucleocapsid protein, scample dilutim, chromogen (TMB) and stop solution as well as concentration. As a result, an indirect ELISA was established to detect antibody against PRRSV. About 200 serum samples were detected by the method and IDEXX ELISA kit, respectively. The agreement ratio between the two method reached at 91%.