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CMC0016 Sigma-Aldrich

BL21(DE3) Electrocompetent 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: electrocompetent
transformation efficiency: ≥5 × 109 cfu/μg
shipped in   dry ice
storage temp.   −70°C


General description

The BL21(DE3) Electrocompetent Cells are the first to offer high efficiency cloning and high level protein expression in the same cell.
Cloning efficiencies are increased 25-1,000 fold relative to other preparations of BL21 cells, which is essential for construction of complex expression libraries.


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

Features and Benefits

The unprecedented transformation efficiency of the BL21(DE3) Electrocompetent Cells (> 5 × 109 cfu/μg) eliminates the need for plasmid transfer from the cloning strain to the expression strain, saving days of work in a typical cloning and expression experiment


• BL21(DE3) electrocompetent 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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Certificate of Origin (COO)

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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(DE3) Electrocompetent Cells

BL21(DE3) Electrocompetent Cells are provided in 25 μl aliquots, sufficient for one reaction. Transformation is carried out in a 0.1 cm gap cuvette. Optimal settings for electroporation are listed in...
Keywords: Antibiotics, Centrifugation, Gene expression, Peptide synthesis, Sterilizations, 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

Peer-Reviewed Papers


Related Products

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Add to Cart

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
CMC0021 OverExpress C41(DE3) Electrocompetent Cells, for the highest protein expression
CMC0022 OverExpress C43(DE3) Electrocompetent Cells, for the highest protein expression
CMR0001 Recovery Medium for Expression, for use with competent cells

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