Product Class: Other

dam–/dcm– Competent E. coli

Product Introduction

Methyltransferase deficient E. coli cells suitable for growth of plasmids free of Dam and Dcm methylation

  • No dry ice surcharge on competent cell shipments
  • Outgrowth medium included
  • Free of animal products
Catalog # Size Concentration
C2925H 20.0 x 0.05 ml
C2925I 6.0 x 0.2 ml

Product Information

Description

Highlights

  • Grow plasmids free of Dam and Dcm methylation
  • Free of animal products
  • Phage T1 resistant (fhuA31)
  • Activity of nonspecific endonuclease I (endA1) eliminated for highest quality plasmid preparations
  • K12 Strain

Transformation Efficiency

1-3 x 106 cfu/μg pUC19 DNA Methyltransferase deficient chemically competent E. coli cells suitable for growth of plasmids free of Dam and Dcm methylation. Note that dam- strains are not recommended as a host for primary cloning/ligation. The dam mutation can result in an increased mutation rate in the cell and a reduction in the transformation efficiency. DNA should be maintained in a dam+ strain unless there is a specific need for DNA free of Dam or Dcm methylation.

Genotype

ara-14 leuB6 fhuA31 lacY1 tsx78 glnV44 galK2 galT22 mcrA dcm-6 hisG4 rfbD1 R(zgb210::Tn10) TetS endA1 rspL136 (StrR) dam13::Tn9 (CamR) xylA-5 mtl-1 thi-1 mcrB1 hsdR2
This product is related to the following categories:
Cloning Competent Cell Strains Products
This product can be used in the following applications:
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

Properties & Usage

Antibiotic for Plasmid Selection

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

Shipping Notes

  • Ships on dry ice

Antibiotic Resistance

  • str
  • nit
  • cam

Features

  • Dam/Dcm methyltransferase free plasmid growth

Application Features


Effect of heat shock time on dam-/dcm- competent E. coli transformation efficiency:Effect of heat shock time on dam-/dcm- 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 dam-/dcm- competent E. coli transformation efficiency: Effect of DNA incubation time on dam-/dcm- 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 -/dcm-competentE.coli was transformed with 100 pg of pUC19 control 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.

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.

Protocols, Manuals & Usage

Protocols

  1. Transformation Protocol (C2925)

Usage & Guidelines

Application Notes

Tools & Resources

Selection Charts

Web Tools

FAQs & Troubleshooting

FAQs

  1. Can I transform unmethylated DNA into dam-/dcm- competent E.coli (C2925)?
  2. Does New England Biolabs offer a methyltransferase free strain of Competent E.coli?
  3. How long should I incubate cells on ice after DNA has been added (NEB #C2925H and NEB #C2925I)?
  4. Is dam-/dcm- (NEB #C2925H/C2925I) resistant to kanamycin?
  5. Is the DNA yield lower using dam-/dcm- strain (C2925)?
  6. What are the solutions/recipes (C2925)?
  7. What are the strain properties (C2925)?
  8. What is the difference between NEB #C2925H and NEB #C2925I?
  9. What is the optimal heat shock time for this strain (NEB #C2925H and NEB #C2925I)?
  10. Which strain of Competent E.coli should I use for general cloning?
  11. Why were the colonies at different size after transformation of dam-/dcm- competent E.coli (C2925)?
  12. How should I calculate the transformation efficiency (C2925)?
  13. Can I store competent cells at -20°C instead of -80°C?
  14. Which kind of transformation tubes should be used?
  15. What volume of DNA can be added into competent cells?
  16. What is the shelf life for this strain (NEB #C2925H and NEB #C2925I)?
  17. Are NEB's competent cells compatible with the “Mix & Go" protocol?
  18. 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?
  19. 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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