不同方法转化大肠杆菌和农杆菌转化效率的研究

Study on the Transforming Efficiency of Escherichia coli and Agrobacterium Transformed by Different Methods

将pBI121质粒采用冻融法和热激法转化大肠杆菌,用冻融法转化农杆菌。经Gus染色和电泳检测,获得了含有pBI121质粒大肠杆菌的DH5α和JM109菌株,以及农杆菌EHA105和LBA4404菌株,同时探讨了影响大肠杆菌和农杆菌转化效率的主要因素。结果表明,大肠杆菌感受态细胞在4℃保存18 h时转化效率较高,用甘油低温冻存的感受态细胞20 d具有感受性,但转化效率较低。农杆菌OD6000.45～0.65时转化效率较高。

Plasmid pBI121 was transformed into Escherichia coli by freeze-thaw method and heat- shock method, and into Agrobacterium using freeze-thaw method. By Gus assay and electrophoresis detection, Escherichia coli DHSα, JM109, and Agrobacterium EHA105, LBA4404, we got the plasmid pBI121. Meanwhile, the main factors influencing transformation efficiency of E. coli and Agrobacterium were discussed. Results showed that E. coli competent cells got high trans- formation efficiency stored at 4 ;C for 18 h. Competent cells stored with glycerin at low temperature for 20 d could be transformed, but the transformation efficiency was lower. Transformation efficiency of Agrobacterium was higher when OD600 was from 0.45 to 0.65.