BL21(DE3)pLysS Competent Cells allow high-efficiency protein expression of any gene that is under the control of a T7 promoter and has a ribosome binding site. BL21(DE3)pLysS is lysogenic for λ-DE3, which contains the T7 bacteriophage gene I, encoding T7 RNA polymerase under the control of the lac UV5 promoter. BL21(DE3)pLysS also contains a plasmid, pLysS, which carries the gene encoding T7 lysozyme. T7 lysozyme lowers the background expression level of target genes under the control of the T7 promoter but does not interfere with the level of expression achieved following induction by IPTG. For researchers performing more than one transformation, competent cells are available in standard format (200µl aliquots). For added convenience, single-use competent cells (50µl aliquots) also are available.
Genotype: F–, ompT, hsdSB (rB–, mB–), dcm, gal, λ(DE3), pLysS, Cmr.
- Studier, F.W. and Moffatt, B.A. (1986) J. Mol. Biol. 189, 113–30.
- Davanloo, P. et al. (1984) Proc. Natl. Acad. Sci. USA 81, 2035–9.
BL21(DE3) is an expression strain suitable for high level induction and expression of genes from any T7 promoter-based expression vector. T7 RNA polymerase expression is induced by the addition of 1mM IPTG to the culture.
What’s in the box?
|Competent Cells Control DNA||L107A||1 × 30μl|
|BL21(DE3)pLysS Competent Cells, >106cfu/μg||L119A||5 × 200μl|
For Research Use Only. Not for Use in Diagnostic Procedures.