Results
Expression, purification and identification of SADS-CoV S protein
To express the S protein of SADS-CoV in vitro , eukaryotic expression of the synthesized S gene was done using the vector pCMV with an Fc tag (Fig 1), then the cell lysates infected by rB or wB was detected by Western Blot with anti-huamn Fc PcAb and porcine anti-SADS-CoV positive or negative serum, respectively. As shown in Fig 2A, a specific band could be detected by Western Blot, indicating that S-Fc protein have been expressed and have good antigenicity. Since the S-Fc protein was confirmed successfully expressed in HEK 293F cells, the S-Fc protein was purified with protein G Resin. As shown in Fig 2B, more 95% purity protein was examined by SDS-PAGE, indicating that purified S-Fc protein can be used to develop ELISA.