OBJECTIVETo explore the conditions for high expression of anti-HBsAg scFv A-15 in E. coli, increase the production of the scFv in the culture medium.

METHODSBy changing induction occasion, concentration of inductor IPTG and induction time, influence of various conditions on expression of anti-HBsAg scFv A-15 was analyzed through ELISA. In addition, the effects of sucrose, glycine and Triton X-100 at different concentrations on the scFv excretion into culture medium was evaluation.

RESULTSThe optimal expression conditions were as follows: the induction was started after culturing for 4 h, the concentration of IPTG was 0.5 mmol/L, and the induction lasted for 8 h. The scFv affinity in culture medium with 0.3 mol/L sucrose, 2% glycine, 1% Triton X-100, 16.78-fold higher, respectively than that without the three chemicals. The final yield of anti-HBsAg scFv A-15 was estimated to be 7.4 mg/L.

CONCLUSIONThe conditions for production of anti-HBsAg scFv A-15 were optimized, which provides a practical method for more efficient production of the scFv in E. coli for further studying structure and function.