Chaperone Competent Cells BL21 Set is a set of E.coli BL21 cells transformed with a chaperone protein plasmid (Chaperone Plasmid Set (TaKaRa Code: D3340)). It can be directly transformed with target protein expression plasmids. E.coli BL21 is derived from B strain, which is deficient in Lon proteinase and ompT outer membrane protease, so that the expressed exogenous proteins have higher stability in this system and are often used to express exogenous proteins. However, exogenous proteins expressed in E. coli often have various problems, such as the formation of insoluble inclusion bodies. The reason is that the protein is not folded correctly.
This manual describes the Chaperone Competent Cells BL21 product, which consists of Eco BL21 cells transformed with a chaperone plasmid set. The cells are shipped and stored at -80 °C and are supplied in multiple 100 µL vials containing different chaperone plasmids.
The document details the recommended thawing, mixing, DNA addition (≤10 ng), heat‑shock steps, recovery in SOC medium, and plating procedures. It also notes incompatibility with T7‑based expression vectors, the prohibition of electroporation, and storage guidelines to maintain high transformation efficiency. This manual is written in Chinese.
| Shipping temperature | -80 °C |
|---|---|
| Storage temperature | -80 °C |
| Cell strain | Eco BL21, protease‑deficient |
| Plasmid packaging | 100 µL ×3 vials per plasmid type |
| T7 promoter compatibility | Not compatible |
| Electroporation use | Not allowed |
| Maximum DNA per transformation | ≤10 ng |
| Typical transformation efficiency | >10⁷ cfu/µg DNA |
They should be stored at -80 °C.
No, the cells do not express T7 RNA polymerase and are not compatible with T7‑based vectors such as the PET series.
Use no more than 10 ng of plasmid DNA per 100 µL of competent cells.
No, electroporation should not be used for these cells.