Product Class: Other

NEB® 5-alpha Competent E. coli (High Efficiency)

Product Introduction

NEB 5-alpha Competent E. coli is a derivative of the popular DH5α. It is T1 phage resistant and endA deficient for high-quality plasmid preparations. 

  • High efficiency strain ideal for a wide variety of applications
  • Available in a wide variety of sizes, including single-use vials, 200 μl vials, 96- and 384- well plate and 12 x 8 tube strips
  • No dry ice surcharge on competent cell shipments
  • Outgrowth medium included
  • Free of animal products
Catalog # Size Concentration
C2987H 20.0 x 0.05 ml
C2987I 6.0 x 0.2 ml
C2987P 1.0 96-well plate (20.0 μl/well)
C2987R 1.0 384-well plate (10.0 μl/well)
C2987U 96.0 x 0.05 ml (12.0 8-well strip)

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Product Information

Description

Highlights

  • DH5α™ derivative
  • Free of animal products
  • 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
  • Resistance to phage T1 (fhuA2)
  • Suitable for blue/white screening by α-complementation of the β-galactosidase gene
  • Reduced recombination of cloned DNA (recA1)
  • K12 Strain

Transformation Efficiency

For C2987H, C2987I, C2987P and C2987U: 1 - 3 x 109 cfu/μg pUC19 DNA
For C2987R: 1 - 5 x 108 cfu/μg pUC19 DNA

Chemically competent E. coli cells suitable for high efficiency transformation in a wide variety of applications. Available in 5 convenient formats:

  • Single-use 50 μl vials
  • 200 μl vials
  • 96-well plate
  • 384-well plate
  • 12 x 8-tube strips: packed in 12 x 8-Strip Microplate Cluster Tube (Costar™ Cluster Tube System)

 

For C2987H, C2987I, C2987P and C2987U, SOC Outgrowth Medium is provided.
For C2987R, Outgrowth Medium 1.5 is provided.

Genotype

fhuA2Δ(argF-lacZ)U169 phoA glnV44 Φ80Δ(lacZ)M15 gyrA96 recA1 relA1 endA1 thi-1 hsdR17
This product is related to the following categories:
Cloning Competent Cell Strains Products,
This product can be used in the following applications:
USER® Cloning,
Applications of USER® and Thermolabile USER II Enzymes,
Transformation,
High-throughput cloning and automation solutions

Reagents Supplied

Reagents Supplied

The following reagents are supplied with this product:

NEB # Component Name Component # Stored at (°C) Amount Concentration
  • C2987R     -80    
      NEB® 5-alpha Competent E. coli (High Efficiency) C2987RVIAL -80 1 x 384-well plate
    (10 μl/well)     		Not Applicable
      Outgrowth Medium 1.5 B9040AVIAL 4 1 x 10 ml Not Applicable
      pUC19 Vector N3041AVIAL -20 1 x 0.025 ml 50 pg/µl

Properties & Usage

Antibiotic for Plasmid Selection

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

Shipping Notes

  • Ships on dry ice

Antibiotic Resistance

  • none

Features

  • Versatile cloning strain
  • DH5α™ derivative

Application Features


DNA effects on transformation efficiency and colony output DNA Effects on Transformation Efficiency and Colony Output:
The optimal amount of DNA to use in a transformation reaction is lower than commonly recognized. Using clean, supercoiled pUC19, the efficiency of transformation is highest in the 100 pg-1 ng range. However, the total colonies which can be obtained from a single transformation reaction increase up to about 100 ng.
Effect of heat shock time on NEB 5-alpha competent E.coli transformation efficiency Effect of heat shock time on NEB 5-alpha competent E.coli transformation efficiency:
50 μl of competent cells were transformed with 100 pg of pUC19 control DNA following the provided High Efficiency Transformation Protocol except heat shock time varied from 0 to 80 seconds.
Effect of DNA incubation time on NEB 5-alpha competent E.coli transformation efficiency Effect of DNA incubation time on NEB 5-alpha competent E.coli transformation efficiency:
50 μl of competent cells were transformed with 100 pg of pUC19 control DNA following the provided High Efficiency Transformation Protocol except DNA incubation time varied from 0 to 40 minutes.
Effect of outgrowth medium on transformation efficiency Effect of outgrowth medium on transformation efficiency:
50 μl of NEB 5-alpha competent E.coli was transformed with 100 pg of pUC19control DNA following the provided High Efficiency Transformation Protocol with the exception of varying the outgrowth medium. NEB SOC outgrowth medium delivers the highest transformation efficiency.
Benefit from the high transformation efficiencies of NEB 5-alpha Benefit from the high transformation efficiencies of NEB 5-alpha:
The transformation efficiencies of NEB 5-alpha and DH5α were compared using each manufacturers' recommended protocols. Values shown are the average of triplicate experiments.

Product Notes

  1. For C2987H, C2987I, C2987P and C2987U, SOC Outgrowth Medium is provided.
    For C2987R, Outgrowth Medium 1.5 is provided.

  2. CAUTION: This product contains DMSO, a hazardous material. Review the MSDS before handling.

  3. 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.

    SOC medium can be stored at either 4°C or Room Temperature depending on how fast it will be used. Storing at Room Temperature is convenient and adequate for short term usage (weeks to a couple of months). For long term storage, we recommend storing at 4°C. Please note that Outgrowth Medium 1.5 supplied with C2987R (1 x 384 well plate format) must only be stored at Room Temperature or crystals will form.

Protocols, Manuals & Usage

Protocols

  1. 5 Minute Transformation Protocol (C2987H/C2987I)
  2. High Efficiency Transformation Protocol (C2987H/C2987I)
  3. High Efficiency Transformation Protocol for 96-well format (C2987P)
  4. 14 Minute Transformation Protocol (C2987H/C2987I)
  5. High Efficiency Transformation Protocol for 96-tube format (C2987U)
  6. High Efficiency Transformation Protocol for 384-well format (C2987R)

Usage & Guidelines

Application Notes

Tools & Resources

Selection Charts

Web Tools

FAQs & Troubleshooting

FAQs

  1. Which competent cell strains are compatible with Gateway® Cloning?
  2. Can I store competent cells at -20°C instead of -80°C?
  3. How can I increase transformation efficiency?
  4. How long should I incubate cells on ice after DNA has been added (NEB #C2987H and NEB #C2987I)?
  5. How should I calculate the transformation efficiency (C2987)?
  6. What are the solutions/recipes (C2987)?
  7. What are the strain properties (C2987)?
  8. What is the difference between NEB #C2987H and NEB #C2987I?
  9. What is the difference between NEB #C2988J and NEB #C2987H?
  10. What is the optimal heat shock time for this strain (NEB #C2987H and NEB #C2987I)?
  11. What type of competent cells are suitable for transformation of DNA constructs created using Gibson Assembly?
  12. Which strain of Competent E.coli should I use for general cloning?
  13. Which kind of transformation tubes should be used?
  14. What volume of DNA can be added into competent cells?
  15. Are NEB's competent cells compatible with the “Mix & Go" protocol?
  16. What is the shelf life for this strain (NEB #C2987H and NEB #C2987I)?
  17. How does the transformation efficiency of the 96-well plate format (NEB #C2987P) compare to the other formats?
  18. What is the optimal heat shock time for the 96-well plate format NEB 5-alpha Competent E.coli (NEB #C2987P)?
  19. I am competing in the iGEM competition. Do you have any products that I should consider from NEB?
  20. What is the optimal heat shock time for the 384-well plate format NEB 5-alpha Competent E. coli (NEB #C2987R)?
  21. What is the optimal heat shock time for the 96-tube format NEB 5-alpha Competent E. coli (NEB #C2987U)?
  22. What type of competent cells are suitable for transformation of DNA constructs created using NEBuilder HiFi DNA Assembly Master Mix?
  23. 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?
  24. How should fragments be prepared for assembly using NEBuilder HiFi?

Quality, Safety & Legal

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.

Specifications

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 controls 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.

Legal and Disclaimers

Products and content are covered by one or more patents, trademarks and/or copyrights owned or controlled by New England Biolabs, Inc (NEB). The use of trademark symbols does not necessarily indicate that the name is trademarked in the country where it is being read; it indicates where the content was originally developed. The use of this product may require the buyer to obtain additional third-party intellectual property rights for certain applications. For more information, please email busdev@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.

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