各种感受态细胞的区别、用途和特征

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1、各种感受态细胞的区别、用途和特征Xl1-Blue菌株基因型：endA1gyrA96(nalR)thi-1recA1relA1lacglnV44F‘[Tn10proAB+lacIqΔ(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–ompTgaldcmlonhsdSB(rB-mB-)λ(DE3[lacIlacUV5-T7gene1ind1sam7nin5])。特点：该菌株用于以T7RNA聚合酶为表达系统的高效外源基因的蛋白表达宿主

2、。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www.bbioo.com]BL21(DE3)ply菌株基因型：F-ompTgaldcmlonhsdSB(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Compet

3、entE.coliFullProductDescriptionBL21Star™E.colistrainsarehigh-performanceBL21hostsdesignedforimprovingproteinyieldinaT7promoter-basedexpressionsystem.BecauseT7RNApolymerasesynthesizesmRNAmorerapidlythanE.coliRNApolymerases,transcriptionfromtheT7promoterisuncoupledtotra

4、nslationinE.coli.ThisresultsinmRNAtranscriptsunprotectedbyribosomes,whicharethensubjecttoenzymaticdegradationbyendogenousRNases(1).Thereducedleveloftranscriptsinthecelloftenleadstogreatlyreducedlevelsofproteinyield(Figure1).TheBL21Star™strainscontainamutationinthegene

5、encodingRNaseE(rne131),whichisoneofthemajorsourcesofthismRNAdegradation(2).BL21Star™cellssignificantlyimprovethestabilityofmRNAtranscriptsandincreaseproteinexpressionyieldfromT7promoter-basedvectors(3)(Figure2).BL21Star™(DE3)isidealforexpressingproteinsthatarenon-toxi

6、ctoE.coli.BL21Star™(DE3)pLysSofferslowerbasal-levelexpressionofheterologousgenesthanBL21Star™(DE3).ItisdesignedforexpressingproteinsthatareslightlygrowthinhibitivetoE.coli.DH5α菌株基因型：F-endA1glnV44thi-1recA1relA1gyrA96deoRnupGΦ80dlacZΔM15Δ(lacZYA-argF)U169,hsdR17(rK-,λ–

7、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www.bbioo.com]JM109菌株基因型：endA1glnV44thi-1relA1gyrA96recA1mcrB+Δ(lac-proAB)e14-[F‘traD36proAB+lacIqlacZΔM15]hsdR17(rK-mK+)。特点：部分抗性缺陷

8、，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。