NEBExpress® Competent E. coli (High Efficiency)

Catalog # Concentration Size List Price Quantity Your Price
C2523H 20 x 0.05 ml $342.00
$307.80
C2523I 6 x 0.2 ml $260.00
$234.00
Catalog # Size List Price Your Price
C2523H 20 x 0.05 ml $342.00
$307.80
C2523I 6 x 0.2 ml $260.00
$234.00
Catalog #
Qty:
 
*On-line ordering is for Canadian customers only. Web pricing is applicable only to orders placed online at www.neb.ca

High efficiency chemically competent E. coli cells suitable for non-T7 protein expression.

  • Deficient in proteases Lon and OmpT
  • Resistant to phage T1 (fhuA2)
  • Free of animal products
  • No dry ice surcharge on competent cell shipments
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Highlights
  • Enhanced BL21 derivative ideal for Plac, Ptac, Ptrc expression vectors
  • Deficient in proteases Lon and OmpT
  • Resistant to phage T1 (fhuA2)
  • Does not restrict methylated DNA (McrA-, McrBC-, EcoBr-m-, Mrr-)
  • Free of animal products
Reagents Supplied

The following reagents are supplied with this product:

NEB # Component Name Component # Stored at (°C) Amount Concentration
  SOC Outgrowth Medium B9020SVIAL 4 1 x 25 ml
  pUC19 Vector N3041AVIAL -20 1 x 0.025 ml 50 pg/µl
  NEBExpress® Competent E. coli (High Efficiency) C2523HVIAL -80 20 x 0.05 ml
  SOC Outgrowth Medium B9020SVIAL 4 1 x 25 ml
  pUC19 Vector N3041AVIAL -20 1 x 0.025 ml 50 pg/µl
  NEBExpress® Competent E. coli (High Efficiency) C2523IVIAL -80 6 x 0.2 ml
Features
  • Versatile non-T7 expression strain
  • Protease deficient
Application Features

Chemically competent E. coli cells suitable for high efficiency transformation and protein expression. Recommended host strain for pMAL Protein Fusion and Purification System.

 

DNA Effects on Transformation Efficiency and Colony Output: C2523_fig1
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 NEBExpress competent E. coli transformation efficiency: C2523a  
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 Express competent E. coli transformation efficiency: C2523b
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.

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
Tetracycline 15 µg/ml
Streptomycin 25 µg/ml

Shipping Notes

  • Ships on dry ice

Antibiotic Resistance

  • nit


Materials Sold Separately
Notes
  • 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.
Quality Control Assay
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]
Legal And Disclaimer

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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