Product Class: Other

BL21 Competent E. coli

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Product Introduction

BL21 Competent E. coli is a widely used non-T7 expression E. coli strain and is suitable for transformation and protein expression. This strain does not express the T7 RNA Polymerase.

  • Ideal for Plac, Ptac, Ptrc ParaBAD expression vectors
  • Protease deficient
  • No dry ice surcharge on competent cell shipments
  • Outgrowth medium included
  • Free of animal products
Catalog # Size Concentration
C2530H 20.0 x 0.05 ml

Product Information

Description

Highlights

  • Routine non-T7 expression
  • Deficient in proteases Lon and OmpT
  • Resistant to phage T1 (fhuA2)
  • B Strain
  • Free of animal products

Transformation Efficiency

1–5 x 107 cfu/μg pUC19 DNA

 

Genotype

fhuA2 [lon] ompT gal [dcm] ΔhsdS
This product is related to the following categories:
Non-T7 Expression,
E. coli Protein Expression Strains Products,
Protein Expression Products,
E. coli Expression Strains Products,
This product can be used in the following applications:
Non-T7 Expression,
Protein Expression in E. Coli,
Protein Expression

Reagents Supplied

Reagents Supplied

The following reagents are supplied with this product:

NEB # Component Name Component # Stored at (°C) Amount Concentration

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

Features

  • Routine non-T7 expression

Product Notes

  1. CAUTION: This product contains DMSO, a hazardous material. Review the MSDS before handling.
  2. 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.
  3. COMPATIBLE EXPRESSION VECTORS/PROMOTERS: Ptac, Ptrc, Plac, PlacUV5, ParaBAD, PrhaBAD, T5-lacO
    Note: Expression from vectors containing a T5-lacO promoter will not be regulated unless the expression vector encodes the lacI gene or a compatible vector expresses LacI or the host strain overproduces LacI (e.g NEB #C3037 NEB Express Iq Competent E. coli)."

Protocols, Manuals & Usage

Protocols

  1. Transformation Protocol (C2530)
  2. 5 Minute Transformation Protocol (C2530)
  3. Protocol for Protein Expression Using BL21 (C2530)
  4. Transformation Protocol (NEB #C2530)

Usage & Guidelines

Tools & Resources

Selection Charts

FAQs & Troubleshooting

FAQs

  1. Does New England Biolabs offer strains of Competent E.coli suited for protein expression?
  2. What are the solutions/recipes (C2530)?
  3. What are the strain properties (C2530)?
  4. Why are there no colonies or no growth in liquid culture (C2530)?
  5. Why is the induced protein insoluble (C2530)?
  6. Why is there no protein visible on gel or no activity (C2530)?
  7. Can I store competent cells at -20°C instead of -80°C?
  8. Which kind of transformation tubes should be used?
  9. What volume of DNA can be added into competent cells?
  10. What is the shelf life for this strain (NEB #C2350H)?
  11. Are NEB's competent cells compatible with the “Mix & Go" protocol?
  12. What is the difference between BL21 and BL21(DE3) competent E.coli cells?
  13. 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?

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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