What are chemically competent cells?
Chemically competent cells are bacteria treated to enhance uptake of foreign DNA compared to normal cells. E. coli is a hardy gram-negative bacterium chosen as a model organism and is frequently used in molecular biology research. To prepare chemically competent cells, E. coli are treated with calcium chloride (CaCl2) to facilitate attachment of foreign plasmid DNA to the cell membrane. Subsequently, these cells are heat-shocked in a water bath at 42°C, which opens the pores of the cell membrane allowing entry of foreign plasmid into the cell (transformation). Chemically competent cells are best suited for general cloning and subcloning applications. Tables 1–3 list the characteristics of the chemically competent E. coli strains.
Learn about the differences between chemically competent and electrocompetent cells
The requirements for efficiency are largely determined by the application. Chemically competent cell transformation efficiency ranges from 1 × 106 to >5 × 109 transformants per μg of DNA. We offer a wide range of chemically competent cells including MAX Efficiency, Library Efficiency, and Subcloning Efficiency™.
High efficiency chemically competent E. coli cells (>109 cfu⁄µg)
If DNA is limited or your experiment has intrinsic challenges, choosing a strain with the highest transformation efficiency will help achieve a positive experimental outcome. A modified Hanahan procedure is used to produce high-quality competent cells with high transformation efficiency which are difficult to achieve with DIY or in-house prepared cells.
Table 1. List of chemically competent cells with highest transformation efficiency
| Strain | Contains F' episome | T1 resistance available | Blue-white screening | Cloning methylated DNA |
|---|---|---|---|---|
| TOP10 family | — | — | ✓ | ✓ |
| DH10B family | — | — | ✓ | ✓ |
| DH10B T1 family | — | ✓ | ✓ | ✓ |
| DH5α family | — | — | ✓ | — |
| DH5α-T1R family | — | ✓ | ✓ | — |
| MAX Efficiency Stbl2 competent cells | — | — | — | ✓ |
| Mach1 T1R family | — | ✓ | ✓ | — |
| OmniMAX 2 T1R chemically competent E. coli | ✓ | ✓ | ✓ | ✓ |
| TOP10F´chemically competent E. coli | ✓ | ✓ | ✓ | ✓ |
| ccdB survival 2 T1R competent cells | — | ✓ | ✓ | ✓ |
| PIR1 chemically competent E. coli | — | — | — | — |
The requirements for efficiency are largely determined by the application. Chemically competent cell transformation efficiency ranges from 1 × 106 to >5 × 109 transformants per μg of DNA. We offer a wide range of chemically competent cells including MAX Efficiency, Library Efficiency, and Subcloning Efficiency™.
Medium efficiency chemically competent E. coli cells (108–109 cfu⁄µg)
For other challenging applications, such as blunt-end cloning, Library Efficiency competent cells can help achieve desired results. For cloning multiple fragments with Gibson Assembly, these cells aid in faster generation of clones.
Table 2. List of chemically competent cells with medium transformation efficiency
| Strain | Contains F' episome | T1 resistance available | Blue-white screening | Cloning methylated DNA |
|---|---|---|---|---|
| MAX Efficiency DH10Bac competent cells | — | — | ✓ | — |
| DH5α family | ✓ | ✓ | ✓ | — |
| TOP10 family | — | — | ✓ | ✓ |
| Stbl3 chemically competent E. coli | — | — | — | ✓ |
| BL21 family | — | — | — | — |
| INVαF´chemically competent E. coli | ✓ | — | ✓ | ✓ |
| MC1061/P3 chemically competent E. coli | — | — | — | ✓ |
| TOP10/P3 chemically competent E. coli | — | — | ✓ | ✓ |
| PIR2 chemically competent E. coli | — | — | — | — |
The requirements for efficiency are largely determined by the application. Chemically competent cell transformation efficiency ranges from 1 × 106 to >5 × 109 transformants per μg of DNA. We offer a wide range of chemically competent cells including MAX Efficiency, Library Efficiency, and Subcloning Efficiency™.
Subcloning efficiency of chemically competent E. coli cells (106–107 cfu⁄µg)
These cells are an economical choice for routine cloning applications, such as propagating vectors.
Table 3. List of chemically competent cells with subcloning efficiency
| Strain | Contains F' episome | T1 resistance available | Blue-white screening | Cloning methylated DNA |
|---|---|---|---|---|
| Subcloning Efficiency DH5α competent cells | — | — | ✓ | — |
| INV110 chemically competent E. coli | ✓ | ✓ | ✓ | — |
The requirements for efficiency are largely determined by the application. Chemically competent cell transformation efficiency ranges from 1 × 106 to >5 × 109 transformants per μg of DNA. We offer a wide range of chemically competent cells including MAX Efficiency, Library Efficiency, and Subcloning Efficiency™.
High efficiency chemically competent E. coli cells (>109 cfu⁄µg)
If DNA is limited or your experiment has intrinsic challenges, choosing a strain with the highest transformation efficiency will help achieve a positive experimental outcome. A modified Hanahan procedure is used to produce high-quality competent cells with high transformation efficiency which are difficult to achieve with DIY or in-house prepared cells.
Table 1. List of chemically competent cells with highest transformation efficiency
| Strain | Contains F' episome | T1 resistance available | Blue-white screening | Cloning methylated DNA |
|---|---|---|---|---|
| TOP10 family | — | — | ✓ | ✓ |
| DH10B family | — | — | ✓ | ✓ |
| DH10B T1 family | — | ✓ | ✓ | ✓ |
| DH5α family | — | — | ✓ | — |
| DH5α-T1R family | — | ✓ | ✓ | — |
| MAX Efficiency Stbl2 competent cells | — | — | — | ✓ |
| Mach1 T1R family | — | ✓ | ✓ | — |
| OmniMAX 2 T1R chemically competent E. coli | ✓ | ✓ | ✓ | ✓ |
| TOP10F´chemically competent E. coli | ✓ | ✓ | ✓ | ✓ |
| ccdB survival 2 T1R competent cells | — | ✓ | ✓ | ✓ |
| PIR1 chemically competent E. coli | — | — | — | — |
The requirements for efficiency are largely determined by the application. Chemically competent cell transformation efficiency ranges from 1 × 106 to >5 × 109 transformants per μg of DNA. We offer a wide range of chemically competent cells including MAX Efficiency, Library Efficiency, and Subcloning Efficiency™.
Medium efficiency chemically competent E. coli cells (108–109 cfu⁄µg)
For other challenging applications, such as blunt-end cloning, Library Efficiency competent cells can help achieve desired results. For cloning multiple fragments with Gibson Assembly, these cells aid in faster generation of clones.
Table 2. List of chemically competent cells with medium transformation efficiency
| Strain | Contains F' episome | T1 resistance available | Blue-white screening | Cloning methylated DNA |
|---|---|---|---|---|
| MAX Efficiency DH10Bac competent cells | — | — | ✓ | — |
| DH5α family | ✓ | ✓ | ✓ | — |
| TOP10 family | — | — | ✓ | ✓ |
| Stbl3 chemically competent E. coli | — | — | — | ✓ |
| BL21 family | — | — | — | — |
| INVαF´chemically competent E. coli | ✓ | — | ✓ | ✓ |
| MC1061/P3 chemically competent E. coli | — | — | — | ✓ |
| TOP10/P3 chemically competent E. coli | — | — | ✓ | ✓ |
| PIR2 chemically competent E. coli | — | — | — | — |
The requirements for efficiency are largely determined by the application. Chemically competent cell transformation efficiency ranges from 1 × 106 to >5 × 109 transformants per μg of DNA. We offer a wide range of chemically competent cells including MAX Efficiency, Library Efficiency, and Subcloning Efficiency™.
Subcloning efficiency of chemically competent E. coli cells (106–107 cfu⁄µg)
These cells are an economical choice for routine cloning applications, such as propagating vectors.
Table 3. List of chemically competent cells with subcloning efficiency
| Strain | Contains F' episome | T1 resistance available | Blue-white screening | Cloning methylated DNA |
|---|---|---|---|---|
| Subcloning Efficiency DH5α competent cells | — | — | ✓ | — |
| INV110 chemically competent E. coli | ✓ | ✓ | ✓ | — |
Chemically competent cells: Formats
To cater to the unique requirements of each project, we offer chemically competent cells in a variety of packaging formats, including One Shot, MultiShot, and standard formats.
Competent cells: Featured products
In addition to competent cells, we offer a broad suite of products for the cloning workflow.
Microbial
media
Explore types of bacterial growth media to use for cloning, plasmid DNA preparation, and protein expression.
Electroporation
cuvettes
Learn more about universal-fit electroporation cuvettes for use with competent cells.
TOPO PCR
cloning kits
Learn more about one-step PCR cloning that combines traditional restriction and ligation cloning.
Gibson Assembly
cloning kits
Gibson Assembly cloning kits provide highly efficient, seamless cloning, enabling the assembly of multiple DNA fragments of varying lengths into any vector.
Resources
Have any questions on competent cells or transformation? Click on the resources listed below to access overviews, videos, genotype guides, and educational resources.
Review rich educational content on transformation workflow, troubleshooting, strategies, and selection guides.
Stay up-to-date on industry trends in molecular cloning with on-demand webinars.
Short articles and digital handbook for cloning applications
Access white papers and technical and application notes on molecular cloning.
Watch instructional videos on troubleshooting tips, how-to videos, and explainers related to molecular cloning.
Get support for your cloning experiments
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Stylesheet for Classic Wide Template adjustments
Stylesheet for Classic Wide Template adjustments