各种感受态细胞的区别、用途和特征.doc

各种感受态细胞的区别、用途和特征Xl1-Blue菌株基因型：endA1 gyrA96(nalR) thi-1 recA1 relA1 lac glnV44 F‘[Tn10 proAB+ lacIq Δ(lacZ)M15] hsdR17(rK- mK+)特点：具有卡那抗性、四环素抗性和氯霉素抗性用途：分子克隆和质粒提取BL21(DE3)菌株基因型：F– ompT gal dcm lon hsdSB(rB- mB-) λ(DE3 [lacI lacUV5-T7 gene 1 ind1 sam7 nin5])特点：该菌株用于以T7 RNA聚合酶为表达系统的高效外源基因的蛋白表达宿主T7噬菌体RNA聚合酶基因的表达受控于λ噬菌体DE3区的lacUV5启动子，该区整合于BL21的染色体上该菌适合于非毒性蛋白的表达用途：蛋白质表达[生物秀-专心做生物 ]BL21(DE3)ply菌株基因型：F- ompT gal dcm lon hsdSB(rB- mB-) λ(DE3) pLysS(cmR)特点：该菌株带有pLysS，具有氯霉素抗性此质粒还有表达T7溶菌酶的基因，T7溶菌酶能够降低目的基因的背景表达水平，但不干扰IPTG诱导的表达。

适合于毒性蛋白和非毒性蛋白的表达用途：蛋白质表达Competent E. coliFull Product Description BL21 Star™ E. coli strains are high-performance BL21 hosts designed for improving protein yield in a T7 promoter-based expression system. Because T7 RNA polymerase synthesizes mRNA more rapidly than E. coli RNA polymerases, transcription from the T7 promoter is uncoupled to translation in E. coli. This results in mRNA transcripts unprotected by ribosomes, which are then subject to enzymatic degradation by endogenous RNases (1). The reduced level of transcripts in the cell often leads to greatly reduced levels of protein yield (Figure1). The BL21 Star™ strains contain a mutation in the gene encoding RNaseE (rne131), which is one of the major sources of this mRNA degradation (2). BL21 Star™ cells significantly improve the stability of mRNA transcripts and increase protein expression yield from T7promoter-based vectors (3) (Figure 2).BL21 Star™(DE3) is ideal for expressing proteins that are non-toxic to E. coli.BL21 Star™(DE3)pLysS offers lower basal-level expression of heterologous genes than BL21 Star™(DE3). It is designed for expressing proteins that are slightly growth inhibitive to E. coli.DH5α菌株基因型：F- endA1 glnV44 thi-1 recA1 relA1 gyrA96 deoR nupG Φ80dlacZΔM15 Δ(lacZYA-argF)U169, hsdR17(rK-, λ–特点：一种常用于质粒克隆的菌株。

其Φ80dlacZΔM15基因的表达产物与pUC载体编码的β-半乳糖苷酶氨基端实现α互补，可用于蓝白斑筛选recA1和 endA1的突变有利于克隆DNA的稳定和高纯度质粒DNA的提取用途：分子克隆、质粒提取和蛋白质表达[生物秀-专心做生物 ]JM109菌株基因型：endA1 glnV44 thi-1 relA1 gyrA96 recA1 mcrB+ Δ(lac-proAB) e14- [F‘ traD36 proAB+ lacIq lacZΔM15]hsdR17(rK-mK+)特点：部分抗性缺陷，适合重复基因表达, 可用于M13克隆序列测定和蓝白斑筛选用途：分子克隆、质粒提取和蛋白质表达友情提示：部分文档来自网络整理，供您参考！文档可复制、编制，期待您的好评与关注！ / 。