大肠杆菌DH5α菌株感受态制备及转化率变化研究

Study on variation of transformation rate of E.coli DH5α competent cells

通过氯化钙法制备大肠杆菌DH5α菌株感受态,讨论了不同保存温度和保存时间对感受态转化率的影响。结果表明,在4℃下保存,8h达到最高转化率;在-20℃和-70℃下保存,均为48h达到最高转化率。通过氯化钙法制备的DH5α菌株感受态细胞,在-20℃条件下简单保存,20d内完全可以满足一般转化研究的要求,不需要复杂的甘油、液氮处理及超低温要求。

The competent cells of E.coli DH5α strain were prepared by calcium chloride,and the variation of transformation rate for different treatment temperatures and times was detected.Experimental results showed that the transformation rate of competent cells stored at 4℃ reached maximum for 8 hours.And the transformation rates reached maximum for 48 hours,when they were stored at-20℃ and-70℃.The competent cells of E.coli DH5α strain prepared by calcium chloride could satisfy general research needs when they were stored directly at-20℃ within 20 days.