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HI-Control BL21(DE3) Chemically Competent Cells

Competent Cells include Control DNA and Recovery Medium, and are packaged as SOLOs (1 transformation per tube). Recovery Medium is also available separately. The specified transformation efficiencies are with pUC DNA, unless indicated otherwise.

HI-Control BL21(DE3) Chemically Competent Cells

Induce high-level protein expression from T7 promoters with tight control over leaky expression, using this strain containing a LacI repressor.
  • Reduce leaky expression: The LacI repressor protein binds to the lacO operator, blocking transcription of downstream genes. In the absence of an induction agent such as lactose sugar or IPTG, target protein expression from the adjacent promoter is greatly reduced.
  • Obtain high protein yields:Both 10G and BL21(DE3)-based strains express high levels of protein. For expression from a T7 promoter, select the HI-Control BL21(DE3) strain. Other lac-based promoters like T5-lac, tac, trc, and lac, can be used in either HI-Control strain.
  • Achieve high efficiency transformations: Highly efficient competent cells give excellent results from small amounts of plasmid DNA.

Size: 12 reactions (SOLOs)

Item ID 60435-1
TBD
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Product information

The HI-Control™ strains are based on E. cloni 10G ( DH10B) and BL21(DE3) strains. These strains harbour a plasmid bearing a constitutive lacI repressor gene, which provides tight control over promoters containing the lacO operator.

  Tightly Control Protein Expression    
  T7 Promoters Non-T7 lac promoters
(T5-lac, tac, trc, lac)
Clone with low background target expression Transformation efficiencies
HI-Control
BL21(DE3)
      ≥ 1×107 cfu/µg
HI-Control
10G
      ≥ 1×109 cfu/µg

Genotypes:

HI-Control BL21 (DE3): F- ompT hsdSB (rB- mB-) gal dcm (DE3) Mini-F lacIq1(GentR)

HI-Control 10G: mcrA Δ(mrr-hsdRMS-mcrBC) endA1 recA1 ɸ80dlacZΔM15 ΔlacX74 araD139 Δ (ara,leu)7697 galU galK rpsL (StrR) nupG λ− tonA Mini-F lacIq1 (GentR)

 

Please note that the SUMO Protease and SUMO Fusion tag are modified from the original native proteins. Native or non-modified control proteins or proteases will not be compatible.

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