中文摘要：

目的 检测重组工程菌pET28a-MAGE-1／HSP70／MAGE-3／BL21（DE3）生物学性状的稳定性。方法 将工程菌菌株连续传50代，每隔10代挑取单克隆菌落进行诱导表达，并计算质粒丢失率。提取不同代次的质粒，扫描电镜观察，检测融合蛋白表达水平，并进行工程菌的染色镜检及生化鉴定。结果 pET28a-MAGE-1／HSP70／MAGE-3／BL21（DE3）融合蛋白工程菌呈典型的大肠杆菌形态，各代次菌的各项检测结果与原始菌种差异无显著意义。结论 重组工程菌pET28a-MAGE-1／HSP70／MAGE-3／BL21（DE3）生物学性状稳定，可作为生产用菌种。

英文摘要：

Objective To study the stability of biological property of recombinant E. coli strain for the expression of MAGE-1/ HSP70/MAGE-3. Methods Subculture the constructed recombinant E. coli strain pET28a-MAGE-1/HSP70/MAGE-3/BL21 （DE3） for 50 passages,and select monoclones every 10 passages for induction and test for losing rate of plasmid. Extract the plasmids of strains of various passages for scanning electron microscopy. Determine the expression level of fusion protein and test for the biochemical property of the recombinant strain. Results Recombinant strain pE128a-MAGE-1/HSP70/MAGE-3/BL21 （DE3） showed typical morphology of E. coli. The test results of the strain of various passages showed no significant difference from those of primary strain. Conclusion Recombinant E. coli strain pET28a-MAGE-1/HSP70/MAGE-3/BL21 （DE3） showed stable biological property and might be used as the bacterial seed for production.