For cloning experiments choose from several high efficiency competent cell strains. These E. coli strains are T1 phage resistant and are endA deficient for high quality plasmid preparations. Additionally, all competent cells from NEB are free of animal products.
NEB offers chemically competent Kluyveromyces lactis cells and variants of this strain that have been tailored for specific protein expression needs. These cells are suitable for transformation with any of our linearized pKLAC series expression vectors.
E. coli for Protein Expression
NEB offers several strains with varying levels of expression control, each with T1 phage resistance and extremely high transformation efficiencies.
- What is LysY?
- What applications are SHuffle® strains useful for?
- Which strain of Competent E. coli should I use for general cloning?
- What does the growth curve of NEB Turbo cells look like compared to DH5α?
- Does New England Biolabs offer strains of Competent E.coli suited for protein expression?
- Does New England Biolabs offer a methyltransferase free strain of Competent E.coli?
- Why did Synthetic Biologist Chris Voigt of MIT choose NEB 10-beta for DNA assembly and cloning?
- What formats are competent cells available in?
- What are the advantages of New England Biolabs' competent cells?
- Which kind of transformation tubes should be used?
- What volume of DNA can be added into competent cells?
- Can I store competent cells at -20°C instead of -80°C?
Bypassing Common Obstacles in Protein Expression
Competent Cells Brochure
The Competent Cells brochure provides information on the different competent cell strains for cloning and protein expression available from NEB.
Protein Expression & Purification Brochure
The Protein Expression and Purification brochure provides information on the advanced tools for protein expression and purification offered by NEB.
- Characteristics of Select E.coli Strains
- Competent Cell Product Comparison
- Competent Cell Selection Guide
- Strain Properties
- Troubleshooting Transformation Reactions
- Additional E. coli Strain Genotypes
- Chemical Transformation Tips
- Convenient Formats of Competent Cells
- Electroporation Tips
- Genetic Markers
- Making Unmethylated (Dam- Dcm-) DNA
- McrA, McrBC and EcoKI Strain Phenotypes
- Restriction of Foreign DNA by E. coli K-12
- Narayanan, A., Ridilla, M. and Yernool, D.A. 2010. Restrained expression, a method to overproduce toxic membrane proteins by exploiting operatorâ€“repressor interactions Pro. Sci. . 20 , PubMedID: , DOI:
- Schlegel, S., Klepsch, M., Gialama, D., Wickström, D., Slotboom, D.J. and de Gier, J. 2010. Revolutionizing membrane protein overexpression in bacteria Micro. Biotech. . 3 , PubMedID: , DOI:
- Wagner, S., Klepsch, M., Schlegel, S., Appel, A., Draheim, R., Tarry, M., Hö, M., van Wijk, K.J., Slotboom, D.J., Persson, J.O. and de Gier, J. 2008. Tuning Escherichia coli for membrane protein overexpression PNAS . 105 , PubMedID: , DOI:
Use this protocol for maximum transformation efficiency.
Follow these tips to get superior results.
NEB has a long history in recombinant protein expression and has developed a wide array of solutions for proteins that are difficult to express.
In this video, see how transformation plating can be fast and easy using glass beads.