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69956 BLR(DE3)pLysS Competent Cells - Novagen

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Catalog NumberPackaging Qty/Pack
69956-3 Plastic ampoule 0.4 ml
69956-4 Glass bottle 1 ml
OverviewBLR is a recA- derivative of BL21 that improves plasmid monomer yields and may help stabilize target plasmids containing repetitive sequences or whose products may cause the loss of the DE3 prophage (1, 2).

DE3 indicates that the host is a lysogen of λDE3, and therefore carries a chromosomal copy of the T7 RNA polymerase gene under control of the lacUV5 promoter. Such strains are suitable for production of protein from target genes cloned in pET vectors by induction with IPTG.

pLysS strains express T7 lysozyme, which further suppresses basal expression of T7 RNA polymerase prior to induction, thus stabilizing pET recombinants encoding target proteins that affect cell growth and viability.
Genotype: F- ompT hsdSB(rB- mB-) gal dcm (DE3) Δ(srl-recA)306::Tn10 pLysS (CamR, TetR)

This product contains genetically modified organisms (GMO). Within the EU GMOs are regulated by Directives 2001/18/EC and 2009/41/EC of the European Parliament and of the Council and their national implementation in the member States respectively. This legislation obliges MilliporeSigma to request certain information about you and the establishment where the GMOs are being handled. Click here for Enduser Declaration (EUD) Form.

This product is sold for internal research use only. Any commercial use of this product, its components, and/or any derivatives thereof (including but not limited to proteins produced using the product or its components) (together and hereinafter the 'EMD Product') requires signature of a written commercial use agreement with EMD Millipore Corporation or its successor-in-interest. Commercial use shall include but not be limited to: (1) use of the EMD Product to manufacture products for sale to third parties; (2) use of the EMD Product to provide services, information, or data to third parties in exchange for consideration; (3) use of the EMD Product for therapeutic, diagnostic or prophylactic purposes (including as part of a device, chip, assay or other product); or (4) resale of the EMD Product, whether or not such EMD Product is resold for research use. Nothing contained herein shall be deemed to represent or warrant that additional third party rights are not required for use of the EMD Product. Please direct any questions on these use restrictions to:
Catalogue Number69956
Brand Family Novagen®
References1. A. Roca (U. of Wisconsin), personal

2. Studier, F. W. (1991) J. Mol. Biol. 219,
Product Information
Guaranteed efficiencyGuaranteed efficiency: > 2 x 10⁶ cfu/μg
Quality LevelMQ100
Biological Information
Physicochemical Information
Materials Information
Toxicological Information
Safety Information according to GHS
Safety Information
Product Usage Statements
Storage and Shipping Information
Ship Code Dry Ice Only
Toxicity Multiple Toxicity Values, refer to MSDS
Storage ≤ -70°C
Avoid freeze/thaw Avoid freeze/thaw
Do not freeze Ok to freeze
Packaging Information
Transport Information
Supplemental Information
Global Trade Item Number
Catalog Number GTIN
69956-3 04055977274035
69956-4 04055977274042


BLR(DE3)pLysS Competent Cells - Novagen SDS


Safety Data Sheet (SDS) 

BLR(DE3)pLysS Competent Cells - Novagen Certificates of Analysis

TitleLot Number


Reference overview
1. A. Roca (U. of Wisconsin), personal

2. Studier, F. W. (1991) J. Mol. Biol. 219,


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  • Min-Ju Kim, et al. (2007) NMR structural studies of interactions of a small, nonpeptidyl Tpo mimic with the thrombopoietin receptor extracellular juxtamembrane and transmembrane domains. Journal of Biological Chemistry 282, 14253-14261.
  • Anthony N. Anselmo, et al. (2006) WNK1 and OSR1 regulate the Na+, K+, 2Cl- cotransporter in HeLa cells. Procedings of the National Academy of Science 103, 10883-10888.
  • Irina Bruck, Roxana E. Georgescu and Mike O'Donnell. (2005) Conserved interactions in the Staphylococcus aureus DNA polC chromosome replication machine. Journal of Biological Chemistry 280, 18152-18162.
  • C. Michael Reynolds, et al. (2005) A phosphoethanolamine transferase specific for the outer 3-deoxy-D-manno-octulosonic acid residue of Escherichia coli lipopolysaccharide. identification of the eptB gene and Ca++ hypersensitivity of an eptB deletion mutant. Journal of Biological Chemistry 280, 21202-21211.
  • An X. Tran, et al. (2004) Periplasmic cleavage and modification of the 1-phosphate group of Helicobacter pylori lipid A. Journal of Biological Chemistry 279, 55780-55791.
  • User Protocols

    TB009 Competent Cells
    TB053 Academic and Non-profit Laboratory Assurance Letter