Cat.No.：D11022A
Price: ￥100
Specifications：
Super competent cell BL21(DE3) is an immediately usable chemical competent cell with the genotype F– ompT hsdSB (rB–, mB–) gal dcm (DE3). It contains the λ DE3 prophage carrying the T7 RNA polymerase gene controlled by the lacUV5 promoter. Under induction by IPTG (isopropyl thiogalactoside) or lactose and its analogues, it can efficiently express the non-toxic foreign genes cloned in expression vectors with the phage T7 promoter (such as pET series). This product is prepared by a special process and uses the optimized competent cell-specific storage solution to ensure the reliability and reproducibility of the experiment. The thermal activation transformation with pUC19 plasmid has a transformation efficiency of > 1x107 cfu/µg.
High-efficiency Transformation: Transformation efficiency > 1x107 cfu/µg pUC19 DNA.
Stable Expression: Prepared through optimized process, it possesses stable genetic characteristics, ensuring the reliability and reproducibility of experiments.
Broad Applicability: Suitable for protein expression of various plasmids such as pET series, pGEX, pMAL, etc.
| Cat. No. | Component | Specification | Quantity |
| B15021A | Supercompetent Cell (E. coli, BL21(DE3)) | 100 μL | 10 |
| B15021A | Supercompetent Cell (E. coli, BL21(DE3)) | 100 μL | 20 |
Stored at -80℃ and transported with dry ice.
This product is suitable for the efficient expression of genes contained in expression vectors with the T7 bacteriophage promoter.
What are the differences between BL21 (DE3), DH5α and TOP10?
BL21 (DE3) is different from the latter two. It is a type of Escherichia coli expression strain and is used for high-level expression of recombinant proteins.
Can it be repeatedly frozen and thawed?
It is strongly not recommended to use after repeated freeze-thaw cycles. The transformation activity of competent cells stored at -80℃ or transported with dry ice can be reduced by more than 50% after one freeze-thaw cycle.
The same vector transformation showed that the number of BL21 (DE3) transformants was less than that of DH5α and TOP10.
It is a normal phenomenon that the transformation activity of expression strain competent cells is lower than that of clone strain competent cells, and it is generally within one order of magnitude. Under the premise of proper preservation of competent cells, the number of transformants obtained from normal vectors used in the experiment can meet the needs of most experimental scenarios.
