基因製備與克隆策略管理知識分析(PPT 61頁)
基因製備與克隆策略管理知識分析(PPT 61頁)目錄:
第一節 目的基因的製備
第二節 目的基因克隆
基因製備與克隆策略管理知識分析(PPT 61頁)簡介:
沒有任何一種克隆方法能夠涵蓋所有好處,克隆步驟:
1)克隆一個基因的方法:cDNA 合成限製性核酸內切酶消化機械剪切 Mechanical shearing
2)加到載體上:選擇寄主和載體係統
平末端連接 Blunt-end ligation
使用連接頭 Use of linker molecules
粘性末端連接 Ligation of cohesive termini
同聚物尾巴 Homopolymer tailing
3)Introducing the recombinant DNA into a host cell:
重組質粒轉化 Transformation with recombinant plasmid DNA
重組噬菌體DNA轉染 Transfection with recombinant phage DNA
DNA體外包裝 Packaging DNA in vitro
★ blunt-end ligation:
S1 nuclease destroy the protruding ends of DNA;
DNA polymerase (klenow fragment) filling the protruding ends of DNA.
Main disadvantage:
1) is an inefficient process, require high concentration DNA for ligation;
2) vector self-ligate to produce circular molecules or the insert/vector DNAs may form concatemers instead of bimolecular recombinants, use phoshpatase (either BAP or CIP) to prevent self-ligation;
3) cloning site disappear in the recombinant DNA
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