Development of a recombinant N-Gp5c fusion protein-based ELISA for detection of antibodies to porcine reproductive and respiratory syndrome virus

► A recombinant fusion protein N-Gp5c (rN5c) of PRRSV was expressed in E. coli. ► An effective ELISA for detection of PRRSV antibody was developed using rN5c. ► The rN5c-ELISA was validated by comparison with immunofluorescent assay and IDEXX PRRS Kit. ► The rN5c-ELISA is simpler to perform, suitable for large scale surveys of PRRSV infection at low cost.