An Economical Alternative
The original BL21-derived competent cells are an economical alternative when high efficiency is not important. The original BL21 cells provide high protein ｅxpression levels and are deficient in the Lon and OmpT proteases. Use these cells for established ｅxpression constructs that have already been cloned and sequenced.
BL21 competent cells are designed for high-level protein ｅxpression using T7 RNA polymerase-based ｅxpression systems.‡‡ Three different derivatives are available to provide varying levels of ｅxpression control.
ｅxpression Control Choices
The BL21(DE3) competent cells are all-purpose strains for high-level protein ｅxpression and easy induction. The BL21(DE3)pLysS competent cells provide tighter control for ｅxpression of toxic proteins. When used with the lambda CE6 bacteriophage, the BL21 cells provide the tightest control of protein ｅxpression, important for extremely toxic proteins. In addition, the BL21 cells can be used for non-T7 RNA polymerase protein ｅxpression systems.
Optimal Protein ｅxpression
All BL21 strains are deficient in the OmpT and Lon proteases, which may interfere with isolation of intact recombinant proteins. Use the BL21 competent cells and its derivatives with T7 promoter-driven vectors, such as the Affinity� pCAL vectors and pET vectors.
BL21 strain: E. coli B F- dcm ompT hsdS(rB- mB-) gal
BL21(DE3) strain: E. coli B F- dcm ompT hsdS(rB- mB-) gal l (DE3)
BL21(DE3)pLysS strain: E. coli B F- dcm ompT hsdS(rB- mB-) gal l (DE3) [pLysS Camr]a
'학술관련 > bacteria' 카테고리의 다른 글
| Spore Forming Bacteria (1) | 2008.12.23 |
|---|---|
| BL21-DE3, BL21-DE3-RIL (1) | 2008.07.02 |
| E.coli BL21 plysS와 E.coli BL21 (0) | 2008.03.25 |
| 고세균 (0) | 2007.09.06 |
| 대장균군 (Coliform Group) (1) | 2007.09.06 |