Highly conservative sequence of salmonid alphavirus E1 gene( 702 bp) was synthesized according to sequences of E1 gene of SAV1,SAV2 and SAV3 published in Gen Bank. It was cloned into prokaryotic expression vector p Cold TF to construct recombinant plasmid. The recombinant plasmid was transformed into E. coli BL21 cells. The expression of recombinant plasmid p Cold TF in E. coli BL21 was induced using IPTG at 1. 0 mmol / L. The target protein of 95 k D was obtained and confirmed by SDS-PAGE and Western blot....