Product Class: Strain

E. coli K12 ER2925

Limit of 1 per order. Although this product is free of charge, freight charges will apply. For US customers, available via phone ordering only (1-800-632-5227). For international customers, please contact your local NEB subsidiary or distributor.
Catalog #SizeConcentration


A suspension of E. coli ER2925 which has been grown in L-Broth and brought to 50% glycerol.


ara-14 leuB6 fhuA31 lacY1 tsx78 glnV44 galK2 galT22 mcrA dcm-6 hisG4 rfbD1 R(zgb210::Tn10)TetS endA1 rpsL136 dam13::Tn9 xylA-5 mtl-1 thi-1 mcrB1 hsdR2

Properties and Usage

Storage Temperature


Supporting Documents

The following is a list of Safety Data Sheet (SDS) that apply to this product to help you use it safely.
The Product Summary Sheet, or Data Card, includes details for how to use the product, as well as details of its formulation and quality controls. The following file naming structure is used to name the majority of these document files: [Catalog Number]Datasheet-Lot[Lot Number]. For those product lots not listed below, please contact NEB at or fill out the Technical Support Form for appropriate document.


  1. Avoid repeated freeze/thaw cycles.
  2. This strain is both Dam- and Dcm- , so it is useful for production of DNA to be cut with Dam or Dcm-sensitive restriction enzymes (1,2). Suppresses many amber mutations when glutamine is acceptable but not the S100 or S7 mutations of λ, e.g., λgt11. Strain is identical to our previous Dam- Dcm- strain GM2163 except that the activity of nonspecific endonuclease I has been abolished, dramatically improving plasmid prep quality in many cases.


  1. Woodcock, D. M. et al. (1989). Nucl. Acids Res. 17, 3469-3478.
  2. Palmer, B. R., and Marinus, M. G. (1994). Gene. 143, 1-12.