中文摘要：

目的优化体外表达旋毛虫抗原基因Ts21的条件。方法比较不同诱导剂（IPTG）浓度、诱导时间、抗生素（氨苄青霉素）浓度及诱导温度等条件下融合蛋白（rMBP-Ts21）的表达水平，选择适宜的表达条件。结果在诱导剂浓度0．3mmol／L、诱导时间3h及诱导温度在20℃的情况下，融合蛋白的表达量最高，占菌体总蛋白的20％；抗生素浓度对融合蛋白表达量无明显影响。结论获得旋毛虫抗原基因Ts21体外表达的适宜条件，为大量制备、纯化该重组抗原奠定基础。

英文摘要：

Objective To optimize the expression conditions in vitro for the antigen gene Ts21 of Trichinella spiralis. Methods The optimal conditions were screened by comparing the fusion protein expression contents in different concentration of inducer （IPTG）, inducing time, concentration of antibiotics （ampicillin）, and inducing temperature. Results The optimal expression conditions in vitro for the Ts21 gene were 0.3 mmol/L WIG, inducing 3 h at 20 ℃. Under these conditions, the portion of the fusion protein accounted for 20% of the total bacterial protein determined by thin-layer gel optical scanning. The concentration of antibiotics had little effect on the expression contents of the fusion protein. Conclusion The optimal expression conditions in vitro for the antigen gene Ts21 of T. spiralis are obtained successfully, which would provide the base for largely expressing and purifying the fusion protein in future.