不同保存方法对重组大肠杆菌菌株活性的影响

目的]探讨不同重组大肠杆菌菌株保存的方法，找出其保存的最适条件。方法]以携带质粒pcDNA3的大肠杆菌DI-lSct为研究对象，分析了4oC冷藏和一70℃冷冻保存对菌株活性的影响。结果]4℃条件下，高稀释度的菌液中活细胞教随着时间的延长而逐渐上升，到第7天时达到最高峰，随后呈现逐渐下降的趋势-70℃条件下，菌液OD600值为0．8，甘油终浓度为8％的处理组，在各保存时间段的活细胞数均显著高于其他组.结论]4℃短期保存重组菌株时，菌液最佳存放时间为7d左右；-70℃长期保存时，宜采用对数生长期的细菌，且保持甘油工作浓度8％为宜。

Effects of Preservation Methods on Activity of Recombinant E.coli

Objective] To explore different preservation methods of recombinant E.coli and find out the optimal conditions for preservation. Method] The recombinant E.coli DH5α transformed pcDNA3 were respectively preserved at 4 ℃ and -70 ℃, and the activity was determined after different time. Result] The number of living E.coli with high dilutions preserved at 4 ℃ was gradually increased within the first 7 d, peaked on Day 7, and then gradually decreased. The number of living E.coli, which were preserved in 8% glycerol at -70 ℃ when OD600 at 0.8, were significantly higher than that of other groups after different preservation time. Conclusion] The optimal storage time was 7 d for recombinant E.coli at 4 ℃. For preservation at -70 ℃, the bacteria should be at logarithmic growth phase and preserved in 8% glycerol.