取0ml大肠杆菌HB101培养物,加至5mLB培养液中 37℃振摇约2h,细菌长至云雾状 倒入15m经冰预冷的离心管,冰浴10min 4℃,4000pm,离心10min 弃上清,在纸巾上倒置1min 沉淀垂悬于冰预冷的1m,0.1 molL Cac2,搅匀 转入1.5ml离心管,冰浴10min 4℃,4000rpm,离心l0min 弃上清,在纸中上倒置1min,垂悬于200μl0. 1mol/L Cac 分装成50山管