NEB® 5-alpha Electrocompetent E. coliProduct information
This product is currently on backorder. We recommend the chemical competent version, NEB 5-alpha Competent E. coli (NEB #C2987H/I) as an alternative. If you can only use electrocompetent cells for your application, please contact our Customer Service Team to explore further options.
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NEB 5-alpha Electrocompetent Competent E. coli is a derivative of the popular DH5α. It is T1 phage resistant and endA deficient for high-quality plasmid preparations.
- Optimized for high efficiency transformation by electroporation
- No dry ice surcharge on competent cell shipments
- Outgrowth medium included
- Free of animal products
- Also available in High efficiency chemical format
- Refer to our Electroporation Tips
- DH5α™ derivative
- Transformation efficiency: >1 x 1010 cfu/µg pUC19 DNA
- Efficient transformation of unmethylated DNA derived from PCR, cDNA and many other sources (hsdR)
- Activity of nonspecific endonuclease I (endA1) eliminated for highest quality plasmid preparations
- Suitable for blue/white screening by α-complementation of the β-galactosidase gene (Φ80Δ lacZM15)
- Resistance to phage T1 (fhuA2)
- Reduced recombination of cloned DNA (recA1)
- K12 Strain
- Free of animal products
NEB 5-alpha Electrocompetent E. coli cells are optimized for high transformation efficiency by electroporation. These cells are ideal for DNA library constructions and all cloning purposes.
GenotypefhuA2Δ(argF-lacZ)U169 phoA glnV44 Φ80Δ (lacZ)M15 gyrA96 recA1 relA1 endA1 thi-1 hsdR17
The following reagents are supplied with this product:
|NEB #||Component Name||Component #||Stored at (°C)||Amount||Concentration|
- Product Categories:
- Cloning Competent Cell Strains Products
Advantages and Features
- Electroporation cuvettes and microcentrifuge tubes should be pre-chilled on ice.
- Electrocompetent cells should be thawed on ice and suspended well by carefully flicking the tubes.
- Once DNA is added to the cells, electroporation can be carried out immediately. It is not necessary to incubate DNA with cells. The maximum recommended volume of a DNA solution to be added is 2.5 µl. Addition of a large volume of DNA decreases transformation efficiency.
- Contaminants such as salts and proteins can lower electroporation efficiency. Ideally, DNA for transformation should be purified and suspended in water or TE. Transformation efficiency is more than 10-fold lower for ligation mixtures than the control pUC19 plasmid due to the presence of ligase and salts. If used directly, ligation reactions should be heat-inactivated at 65°C for 20 min and then diluted 10-fold. For optimal results, spin columns (NEB #T1030) are recommended for cleanup of ligation reactions.
- Electroporation conditions vary with different cuvettes and electroporators. If you are using electroporators or cuvettes not specified in the protocol, you may need to optimize the electroporation conditions. Cuvettes with 1mm gap are recommended (e.g. BTX Model 610/613 and Bio-Rad #165-2089). Higher voltage is required for cuvettes with 2 mm gap.
- Arcing may occur due to high concentration of salts or air bubbles.
- It is essential to add recovery medium to the cells immediately after electroporation. One minute delay can cause a 3-fold reduction in efficiency.
Properties & Usage
Antibiotic for Plasmid Selection
|Antibiotics for Plasmid Selection||Working Concentration|
- Ships on dry ice
- CAUTION: This product contains DMSO, a hazardous material. Review the MSDS before handling.
- STORAGE AND HANDLING: Competent cells should be stored at -80°C. Storage at -20°C will result in a significant decrease in transformation efficiency. Cells lose efficiency whenever they are warmed above -80°C, even if they do not thaw.
Protocols, Manuals & Usage
Usage & Guidelines
Tools & Resources
FAQs & Troubleshooting
- How should I calculate the Electrotransformation efficiency (C2989)?
- What are the solutions/recipes (C2989)?
- What are the strain properties (C2989)?
- How should I store SOC Outgrowth Medium? The SOC I received with my competent cells recommends storage at either room temperature or 4°C, however, when I purchase it as a stand alone product, it recommends storing it at 4°C. Which is better?
- How should fragments be prepared for assembly using NEBuilder HiFi?
Citations & Technical Literature
- Singh A, Minia I, Droll D, Fadda A, Clayton C, Erben E (2014) Trypanosome MKT1 and the RNA-binding protein ZC3H11: interactions and potential roles in post-transcriptional regulatory networks Nucleic Acids Res; 42(7), 4652-68. PubMedID: 24470144, DOI: 10.1093/nar/gkt1416
Quality, Safety & Legal
Quality Assurance StatementQuality Control tests are performed on each new lot of NEB product to meet the specifications designated for it. Specifications and individual lot data from the tests that are performed for this particular product can be found and downloaded on the Product Specification Sheet, Certificate of Analysis, data card or product manual. Further information regarding NEB product quality can be found here.
SpecificationsThe Specification sheet is a document that includes the storage temperature, shelf life and the specifications designated for the product. The following file naming structure is used to name these document files: [Product Number]_[Size]_[Version]
Certificate Of AnalysisThe Certificate of Analysis (COA) is a signed document that includes the storage temperature, expiration date and quality controls for an individual lot. The following file naming structure is used to name these document files: [Product Number]_[Size]_[Version]_[Lot Number]
Safety DataSheetsThe following is a list of Safety Data Sheet (SDS) that apply to this product to help you use it safely.
NEB® 5-alpha Electrocompetent E. coli
SOC Outgrowth Medium
Legal and DisclaimersThis product is covered by one or more patents, trademarks and/or copyrights owned or controlled by New England Biolabs, Inc (NEB).
While NEB develops and validates its products for various applications, the use of this product may require the buyer to obtain additional third party intellectual property rights for certain applications.
For more information about commercial rights, please contact NEB's Global Business Development team at [email protected]neb.com.
This product is intended for research purposes only. This product is not intended to be used for therapeutic or diagnostic purposes in humans or animals.
New England Biolabs (NEB) is committed to practicing ethical science – we believe it is our job as researchers to ask the important questions that when answered will help preserve our quality of life and the world that we live in. However, this research should always be done in safe and ethical manner. Learn more.
The supporting documents available for this product can be downloaded below.