Abstract: 【Objective】 The objective of the experiment is to express and purify E. granulosus (Eg) heat shock protein 70 (EgHsp70) in E. coli and prepare the antibody against E. granulosus. 【Methods】 EgHsp70 gene was amplified by PCR and cloned into prokaryotic expression vector pMAL-p2x, and the recombinant plasmid was transformed into E. coil BL-21. The soluble expression conditions of fusion protein were optimized by induction with different concentrations, of IPTG different temperatures and cultivation times. The expressed fusion protein was purified by Mal-tag Magnetic Beads. To prepare the anti-serum, New Zealand white rabbits were immunized with purified EgHsp70 protein via hypodermic and volar. Western blot was used to determine the serum’s specificity against EgHsp70 and native proteins. The serum titers were analyzed by ELISA. 【Results】 Full-length of EgHsp70 gene had an open reading frame of 765 bps encoding a protein mass of 68.6 kD. Restriction endonuclease analysis and DNA sequencing showed that EgHsp70 was cloned into the plasmid pMAL-p2x. Based on the optimization experiments, it was concluded that the best soluble expression conditions for the EgHsp70 protein are using 0.3 mmol ?L-1 IPTG when bacterial cells growing to OD600 0.6 and induced for 4 h at 30℃. ELISA and Western blotting showed that the titers of the anti-serum were above 1﹕256 000, and the anti-serum could specifically bind with EgHsp70 protein and native proteins. 【Conclusion】 The EgHsp70 fusion protein was obtained by expressing in E.coli and purifying, and the antibody against EgHsp70 was prepared with the fusion protein immunized New Zealand white rabbits. This work will provide an antigen and detection antibody for further study on the EgHsp70 function. The protein is immunogenic and can be a vaccine candidate against Echinococcus infection. 

Key words: Echinococcus granulosus (Eg), heat shock protein 70(Hsp70), antiserum