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目的 :探讨导致部分质粒转化和抽提失败的原因。方法 :使用同一批DH5 α细菌制备感受态 ,转化、碱裂解法抽提和鉴定两种质粒 ,经抗性LB琼脂平板筛选和菌落分析 ,对照成功抽提和鉴定的质粒 ,分析部分质粒反复转化和抽提失败的原因。结果 :发现在该抽提失败的质粒所转化的抗性LB琼脂平板上存在两种菌落 ,大量白色菌落为表皮葡萄球菌 ,其过夜振摇产物经碱裂解法抽提质粒失败 ;极少数淡黄色菌落为大肠杆菌 ,经鉴定 ,质粒抽提成功。结论 :隐蔽的表皮葡萄球菌污染可能是导致部分质粒反复抽提失败的重要原因。
OBJECTIVE: To investigate the causes of some plasmid transformation and extraction failure. METHODS: Two plasmids were extracted and identified by using the same batch of DH5α bacteria. The plasmids were extracted and identified by resistant LB agar plates and colony analysis, and some plasmids were repeatedly transformed And extraction of the reasons for the failure. RESULTS: Two colonies were found on the resistant LB agar plates transformed with failed plasmids. A large number of white colonies were Staphylococcus epidermidis. The overnight shake-out products failed to extract plasmids by alkaline lysis. Very few yellowish-yellow Colonies for E. coli, identified, plasmid extraction success. Conclusion: The concealed staphylococcus epidermidis contamination may be an important reason for the failure of repeated extraction of some plasmids.