Abstract: According to published cDNA sequence of E2 gene in GenBank of CSFV Shimen and C strain, the synthesized specific primers was designed. E2 gene fragments of classical swine fever virus Guizhou strain were amplified by extraction tissue RNA of the suspected CSF dead and RTPCR. The PCR products were sequenced and comparatively analyzed. The products of RTPCR were cloned into pMD18T vector to form recombinants pMD18TE2 and subcloned into prokaryotic expressing vector pET32a(+). The pET32aE2 was transformed into the E. coli strain BL21(DE3) and the expression of the E2 protein was induced. After analysis by SDSPAGE electrophoresis of the induced expressed protein and Western blot, we get about 58 kDa protein in line with the expected size. Through further extracting and purifying the target protein, the expressed protein was used to immunize mice by adding adjuvant, and then the antibody titers of mice were detected. The results showed that the target protein induced antiCSF antibody in mice. This study laid the foundation for the research of subunit vaccine of swine fever.

Key words: CSFV, E2 gene, prokaryotic expression, immunogenicity