目的 :构建新型高效真核表达载体 ,实现人源化鼠抗人纤维蛋白单链抗体 低分子量尿激酶 (IIn UK)在CHO细胞中的高表达。方法 :利用常规分子生物学方法 ,通过对neo基因的表达进行不同程度的弱化 ,构建了一系列新型真核表达载体 ,以IIn UK融合基因为目的基因 ,比较这些真核表达载体实现外源基因高表达的能力 ,然后挑选高表达的克隆 ,通过MTX加压扩增 ,以提高IIn UK融合基因的拷贝数及表达水平。结果与讨论 :构建了 5种新型真核表达载体 ,并筛选出优化的真核表达载体 ,通过MTX加压扩增 ,实现了IIn UK融合基因在CHO细胞中的高表达 ,表达量达到 10 μg/ (10 6细胞·2 4h )。 OBJECTIVE: To construct a new highly efficient eukaryotic expression vector and achieve high expression of humanized anti-human fibrin scFv low molecular weight urokinase (IIn UK) in CHO cells. Methods: A series of novel eukaryotic expression vectors were constructed by using conventional molecular biology methods to attenuate the expression of neo gene. The fusion gene IIn UK was used as the target gene, and the eukaryotic expression vectors were compared to achieve foreign genes High expression of the ability, and then select the high expression of clones by MTX pressure amplification, in order to improve IIn UK fusion gene copy number and expression levels. RESULTS AND DISCUSSION: Five novel eukaryotic expression vectors were constructed and optimized eukaryotic expression vector was screened. The expression of IIn UK fusion gene in CHO cells was achieved by MTX pressurized amplification, and the expression level reached 10 μg / (10 6 cells · 24 h).