Description
Stabilise toxic sequences behind T7 or lac-based promoters with this strain containing a LacI repressor, providing tight control over leaky expression. 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.
Key features
- 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.
Product information
The HI-Control™ strains are based on E. cloni 10G ( DH10B) and BL21(DE3) strains. These strains harbor 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) |
X | X | ≥ 1×107 cfu/µg |
HI-Control 10G |
X | X | ≥ 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)
Product specifications and usage
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.
SDS
MANUAL