摘要
目的：分析大肠杆菌JM109感受态形成因素,提高转化效率。方法：采用不同生长状态、不同转化溶液、不同保存时间及热激处理时间的细菌制备感受态,分析转化效率。结果：以20mmol/L MgCl2＋80mmol/L CaCl2为处理液,经活化培养OD600为0.82的菌液制备感受态细胞,4℃放置12-24h之内,42℃热激处理60s,转化效率最高,可达9.8×10^6-1.2×10^7cfu/μg DNA（pUC19）。随着质粒长度增加,转化效率下降。结论：感受态细胞形成与生长状态关系密切,金属离子、有机溶剂对感受态的形成影响显著。感受态形成过程中,细胞可能发生了一系列的生理变化。
Objective：Analyzing the affecting factors of forming competent cells of Escherichia coli JM109 to increase transformation efficiency.Methods： A series of Escherichia coli JM109 competent cells were produced in different conditions,including growth status,transformation solutions,storing time at 4℃,activating time at 42℃,plasmid length.Different effects on transformation ability of competent Escherichia coli JM109 were evaluated. Result： The highest transformation ability was obtained when the activated cells was cultured to an OD600 0.82, then prepared with 20mmol/L MgCl2 and 80 mmol/L CaCl2 ,kept at 4℃ between 12h to 24h, hot shocked at 42℃ for 60s. The transformation efficiency for optimized protocol was found to be as high as between 9.8×10^6 to 1.2×10^7 cfu/μg DNA （pUC19）. The lower efficiency was, the longer the length d the plamid was. Conclusion： The formation of the competent cells was concerned with growth status, some metal ions and organic solutions. The physiologic change could take place in the process of forming competent cells.
出处
《生物技术》
CAS
CSCD
2007年第2期37-40,共4页
Biotechnology
