Abstract: 【Objective】The E2 gene of Classical swine fever virus was expressed in prokaryotic expression system to obtain soluble fusion protein. 【Method】 Four antigen regions of E2 gene were amplified from recombinant plasmid S21 by the Polymerase Chain Reaction (PCR). The four amplified fragments were cloned into pMAL-P2X vector, respectively. It was identified that the position and the size and the reading frame of the four recombinant vectors were all correct by RCR, restriction digestion and the sequence analysis. Then the four recombinant vectors were transducted into four expression germs and 16 strains of germs were obtained. 【Results】SDS-PAGE indicated that these germs could express antigen region of E2 gene of CSFV and Western-blot indicated that these objective proteins could be recognized by the positive serum of CSFV and monoclonal antibody which is to E2 gene of CSFV. 【Conclusion】The antigen regions of the aimed gene were selected to be expressed, which could benefit the expression of soluble fusion proteins, and the speciality of serological reaction is satisfied.

Key words: Classical swine fever virus, Antigen region of E2 gene, Construction and expression