Product Class: Other

NEB® Turbo Electrocompetent E. coli

Also available in chemically-competent format

Product Introduction

E. coli cells featuring fast colony growth (6.5 hours)

  • Tight expression control (lacIq)
  • Isolate DNA after only 4 hours of growth
  • 5-minute transformation protocol with AmpR plasmids
  • Clone toxic genes
  • No dry ice surcharge on competent cell shipments
  • Outgrowth medium included
  • Free of animal products
Catalog # Size Concentration
C2986K 6 x 0.1 ml/tube 0 mg/ml

Product Information



  • Transformation efficiency 1 x 1010cfu/µg pUC19 DNA
  • Tight control of expression by lacIq allows potentially toxic genes to be cloned
  • Highest growth rate on agar plates - visible colonies 6.5 hours after transformation
  • Activity of nonspecific endonuclease I (endA) eliminated for highest quality plasmid preparations
  • Resistance to phage T1 (fhuA2)
  • Suitable for blue/white screening by α-complementation of the β-galactosidase gene
  • Isolate DNA after 4 hours of growth from a single overnight colony
  • EcoKr-m-, McrBC-
  • K12 Strain
NEB Turbo Electrocompetent E. coli cells are suitable for high efficiency electroporation and rapid colony growth. These cells are ideal for DNA library constructions and all cloning purposes.


F' proA+B+ lacIq ∆lacZM15 / fhuA2  ∆(lac-proAB)  glnV galK16 galE15  R(zgb-210::Tn10)TetS  endA1 thi-1 ∆(hsdS-mcrB)5  

Reagents Supplied

The following reagents are supplied with this product:

Store at (°C) Concentration
SOC Outgrowth Medium 4 1 X
pUC19 Vector -20 0.05 ng/μl
Product Categories:
Cloning Strains
E.coli Protein Expression

Advantages and Features


Electroporation Tips
  1. Electroporation cuvettes and microcentrifuge tubes should be pre-chilled on ice. 
  2. Electrocompetent cells should be thawed on ice and suspended well by carefully flicking the tubes. 
  3. 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. 
  4. 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 than10-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. 
  5. Electroporation conditions vary with different cuvettes and electroporator. If you are using electroporators 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. 
  6. Arcing may occur due to high concentration of salts or air bubbles. 
  7. It is essential to add recovery medium to the cells immediately after electroporation. One minute delay can cause a 3-fold reduction in efficiency. 
  8. Cold and dry selection plates lead to lower transformation efficiency. Pre-warm plates at 37°C for 1 hour. Using 37°C pre-warmed recovery medium increases the efficiency by about 20%. 
  9. Refreeze unused cells in a dry ice/ethanol bath for 5 min and then store at -80°C. Do not use liquid nitrogen. Additional freeze-thaw cycles result in lower transformation efficiency.

Application Features

DNA Effects of Transformation Efficiency and Colony Output:DNA Effects of Transformation Efficiency and Colony Output:
Electroporation efficiency remains extremely high up to about 1 ng of input DNA, then decreases at higher DNA concentrations.

Properties and Usage

Antibiotics for Plasmid Selection Working Concentration
Ampicillin 100 μg/ml
Carbenicillin 100 μg/ml
Chloramphenicol 33 μg/ml
Kanamycin 30 μg/ml
Tetracycline 15 μg/ml
Streptomycin 25 μg/ml

Storage Temperature


Shipping Notes

  • Ships on dry ice

Antibiotic Resistance

  • nit


  1. 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.

Faqs & Tech Tips


  1. How should I calculate the Electrotransformation efficiency (C2986)?
  2. What are the solutions/recipes (C2986)?
  3. What are the strain properties (C2986)?
  4. Can any NEB competent cells help with the generation of custom phage libraries? An F factor is required for such libraries.
  5. 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?

Protocols & Manuals


  1. Electroporation Protocol (C2986)


The Product Summary Sheet, or Data Card, includes details for how to use the product, as well as details of its formulation and quality controls. The following file naming structure is used to name the majority of these document files: [Catalog Number]Datasheet-Lot[Lot Number]. For those product lots not listed below, please contact NEB at or fill out the Technical Support Form for appropriate document.)

Other Tools & Resources

Selection Charts

Usage Guildelines & Tips

Interactive Tools

Quality & Safety

Quality Assurance Statement

Quality 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.


The 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 Analysis

The Certificate of Analysis (COA) is a signed document that includes the storage temperature, expiration date and quality control's for an individual lot. The following file naming structure is used to name these document files: [Product Number]_[Size]_[Version]_[Lot Number]

Safety DataSheets

The following is a list of Safety Data Sheet (SDS) that apply to this product to help you use it safely.