| Strain |
Genotype |
| AR58 |
sup0 galK2 galE::Tn10 (λcI857 ΔH1 bio– uvrB kil– cIII–) Strr |
| 10GS |
F- mcrA Δ(mrr-hsdRMS-mcrBC) endA1 recA1 Φ80dlacZΔM15 ΔlacX74 araD139 Δ(ara,leu)7697 galU galK rpsL nupG λ- tonA/Mini-F lacIq1(Gentr) |
- The HI-Control 10G cells contain a single-copy BAC plasmid harboring a specially engineered version of the lacIq1 repressor allele. The lacIq1 allele expresses ~170-fold more lac repressor protein than the wild-type lacI gene.
- For stable cloning of T7 protein expression plasmids.
- Resistant to phage T1.
|
| Spec shuffle BL21 NEBC3028H T7 |
E. coli B F– ompT gal dcm lon hsdSB(rB–mB–) [malB+]K-12(λS) |
Ø an E. coli B strain carrying the T7 RNA polymerase gene in the araB locus of the araBAD operonq.
Ø Transformed plasmids containing T7 promoter driven expression are repressed until L-arabinose induction of T7 RNA polymerase.
Ø Maximal expression is lower than that of BL21(DE3) (customer support 10/2012)
Ø Derived from BL21.
Ø See the product page for more information.
Ø Brian Caliendo (Voigt lab) reported trouble getting the Datsenko and Wanner (2000) plasmid pCP20 to transform into this strain, when other strains transformed fine. Cause is unknown |
| BL21(DE3) pLysS |
E. coli str. B F– ompT gal dcm lon hsdSB(rB–mB–) λ(DE3 [lacI lacUV5-T7p07 ind1 sam7 nin5]) [malB+]K-12(λS) pLysS[T7p20 orip15A](CmR) |
Ø pLysS plasmid chloramphenicol resistant; grow with chloramphenicol to retain plasmid.
Ø Chloramphenicol resistant
Ø The pLysS plasmid encodes T7 phage lysozyme, an inhibitor for T7 polymerase which reduces and almost eliminates expression from transformed T7 promoter containing plasmids when not induced.
Ø see Moffatt87 for details of pLysS and pLysE plasmids |
| 48SG |
|
|
| NovaBlue |
endA1 hsdR17 (rK12– mK12+) supE44 thi-1 recA1 gyrA96 relA1 lac Fʹ[proA+B+ lacIqZΔM15::Tn10] (TetR) |
| Ø NovaBlue is a K-12 strain ideally suited as an initial cloning host due to its high transformation efficiency, blue/white screening capability (with appropriate plasmids) and recA endA mutations. |
| Rosetta2(DE3) |
F- ompT hsdSB(rB- mB-) gal dcm (DE3) pRARE2 (CamR) |
Ø Novagen's Rosetta™ 2 host strains are BL21 derivatives designed to enhance the expression of eukaryotic proteins that contain codons rarely used in E. coli.
Ø Rosetta™ 2 host strains are BL21 derivatives designed to enhance the expression of eukaryotic proteins that contain codons rarely used in E. coli. These strains supply tRNAs for 7 rare codones (AGA, AGG, AUA, CUA, GGA, CCC, and CGG) on a compatible chloramphenicol-resistant plasmid. The tRNA genes are driven by their native promoters.
Ø
Ø DE3 indicates that the host is a lysogen of λDE3, and therefore carries a chromosomal copy of the T7 RNA polymerase gene under control of the lacUV5 promoter. Such strains are suitable for production of protein from target genes cloned in pET vectors by induction with ıptg |
| SG13009 |
SG13009 strains are derived from E. coli K12 and have the phenotype NaIS , StrS , RifS , Thi- , Lac- , Ara+, Gal+, Mtl- , F- , RecA+, Uvr+ , Lon+. |
- Both strains harbor a plasmid (pREP4) containing a gene that confers kanamycin resistance, Kmr .
- Both strains are prototrophs and can grow on salt agar supplemented with 10 µg/ml thiamine-HCl. They do not require additional growth additives such as amino acids and nucleotide bases.
- Both strains are sensitive to the following: Streptomycin 100 µg/ml Rifampicin 50 µg/ml Nalidixic Acid 20 µg/ml They therefore have no mutations in rpsL, rpoB, and gyrA.
- Both strains cannot metabolize the following: Lactose (Lacñ ) Mannitol (Mtlñ ) i. e. they contain mutations in the lac and mtl genes.
- Data on other genes related to carbohydrate metabolism indicate that the TCA-cycle enzymes correspond to those of the wild type.
|
| DH5α |
F– endA1 glnV44 thi 1 recA1 relA1 gyrA96 deoR nupG purB20 φ80dlacZΔM15 Δ(lacZYA-argF)U169, hsdR17(rK–mK+), λ– |
Ø A Hoffman-Berling 1100 strain derivative (Meselson68)
Ø Promega also lists phoA
Ø Thiamine, arginine auxotroph
Ø Lactose nonutilizing
Ø Nalidixic acid resistant
Ø Recombination-deficient
Ø Relaxed phenotype
Ø Endonuclease A deficient
Ø Constitutive deoxyribose synthesis, good for cloning large plasmids.
Ø Amber suppressor UAG>CAG(Gln).
Ø Slow growth in M9 medium due to purB-20
|
| BL21(DE3) |
E. coli str. B F– ompT gal dcm lon hsdSB(rB–mB–) λ(DE3 [lacI lacUV5-T7p07 ind1 sam7 nin5]) [malB+]K-12(λS) |
Ø an E. coli B strain with DE3, a λ prophage carrying the T7 RNA polymerase gene and lacIq
Ø Transformed plasmids containing T7 promoter driven expression are repressed until IPTG induction of T7 RNA polymerase from a lac promoter.
Ø Derived from B834 (Wood, 1966) by transducing to Met+.
Ø See the original Studier paper or the summary in Methods in Enzymology for more details.
Ø Whole genome sequence available |
| XL1-Blue (Stratagene) |
endA1 gyrA96(nalR) thi-1 recA1 relA1 lac glnV44 F'[ ::Tn10 proAB+ lacIq Δ(lacZ)M15] hsdR17(rK- mK+) |
Ø nalidixic acid resistant
Ø tetracycline resistant (carried on the F plasmid)
|