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CMC0015 Sigma-Aldrich

BL21(DE3) pLysE Chemically Competent Cells

for protein expression

  •  NACRES NA.85



Related Categories Cloning and Expression, Molecular Biology, Transformation of Bacteria More...
grade   for molecular biology
cell transformation   competent cell type: chemically competent
transformation efficiency: ≥1 x 107 cfu/μg
shipped in   dry ice
storage temp.   −70°C


General description

The BL21(DE3) pLysE Chemically Competent Cells produce T7 lysozyme to repress low-level transcription from the T7 promoter prior to IPTG induction, helping to stabilize inserts coding for deleterious products.
These cells have a higher level of repression by T7 lysozyme, offering the greatest control over expression of inserts.


F – ompT hsdSB (rB- mB-) gal dcm (DE3)

Features and Benefits

• a transformation efficiency of >1 × 107 cfu/μg.
• economical prices
• offering superior value for everyday protein expression work.


• BL21(DE3) pLysE chemically competent cells
• pUC 19 transformation control DNA
• recovery medium for expression

Safety & Documentation

Safety Information

UN 3245 9


Certificate of Analysis (COA)

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Protocols & Articles


Competent Cell Selection & E. coli Markers Guide

We offer a range of Escherichia coli bacterial cells made competent with the highest efficiencies by optimized procedure specific to each strain. Choose from 24 new competent cells for a wide variety...
Keywords: Bacterial conjugations, Cloning, Gene expression, Methylations, Recombination, Transcription, transformation

Molecular Biology Handbook

Molecular Biology is the science that aims to understand biological activity at the molecular level. These biological activities usually involve the plant or animal cell, and the nucleic acids and pr...
Keywords: Cell culture, Cell signaling, Cloning, Detection methods, Electrophoresis, Gel electrophoresis, Gene expression, Genetics, Molecular biology, Molecular biology techniques, Nucleic acid hybridization, Nucleic acid purification, Polymerase chain reaction - quantitative, Protein electrophoresis, Purification, Transfection, Western blot, transformation


BL21 Chemically Competent Cells

BL21 Chemically Competent Cells are transformed in 40 μL reactions. Cells are packaged with sufficient volumes for 1, 2, or 4 reactions per tube.
Keywords: Antibiotics, Centrifugation, Gene expression, transformation

Selecting Correctly Expressing Recombinants

Blue / White colony screening is a strategy to quickly and easily distinguish between recombinant and non-recombinant colonies. It requires a special vector and a special strain of E. coli. It is par...
Keywords: AGE, Amplification, Antibiotics, Cell disruption, Centrifugation, Cloning, Degradations, Detergents, Diagnostic, Digestions, Electrophoresis, Gel electrophoresis, Molecular biology, Peptide synthesis, Phase transitions, Polymerase chain reaction, Precipitation, Purification, Sequencing, Transfection, transformation

Transforming E. coli with Engineered Plasmid

Inoue and colleagues developed this method in 1990. It works well for many strains commonly used in cloning. The original method calls for growing the overnight E. coli cultures at 18°C. We find that...
Keywords: Antibiotics, Centrifugation, Cloning, Peptide synthesis, Phase transitions, transformation

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L3022 LB Broth (Lennox), Highly-referenced microbial growth powder medium, low salt, suitable for salt-sensitive E.coli culture.
L2897 LB Broth with agar (Lennox), Highly-referenced microbial growth powder medium with Agar, low salt, suitable for salt-sensitive E. coli culture.
L5542 LB Agar Plates, pre-poured LB agar plates for E. coli
CMC0014 BL21(DE3) Chemically Competent Cells, for protein expression
CMC0018 OverExpress C41(DE3) pLysS Chemically Competent Cells, for the highest protein expression
CMC0023 CONTROLLER SIG10 Chemically Competent Cells, for controlled protein expression
CMC0024 CONTROLLER BL21(DE3) Chemically Competent Cells, for controlled protein expression
CMR0001 Recovery Medium for Expression, for use with competent cells

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