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CMC0024 Sigma-Aldrich

CONTROLLER BL21(DE3) Chemically Competent Cells

for controlled protein expression

  •  NACRES NA.85

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Properties

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

Description

General description

The CONTROLLER BL21(DE3) Chemically Competent Cells are an E. coli strain optimized for high efficiency transformation.
They are ideal for cloning and propagation of plasmid clones. They give high yield and high quality plasmid DNA due to the endA1 mutation.

Features and Benefits

• Reduce leaky expression: The LacI repressor protein binds to the lacO operator to block transcription of downstream genes. In the absence of an induction agent such as lactose sugar or IPTG, target protein expression from the adjacent promoter will be greatly reduced.
• High protein yields: Both 10G and BL21(DE3)-based strains are noted for their ability to express high levels of protein. For expression from a T7 promoter please select the HI-Control BL21(DE3) strain. This strain also is deficient in proteases, yielding more stable protein preparations. Most other promoters can be used in either HI-Control strain.
• Terrific efficiency: The simple, reliable heat-shock procedure for chemical transformation gives excellent results from small amounts of plasmid DNA.

Components

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


Safety & Documentation

Safety Information

RIDADR 
UN 3245 9

Documents

Certificate of Analysis (COA)

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Protocols & Articles

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

Protocols

CONTROLLER Chemically Competent Cells

Sigma CONTROLLER Chemically Competent Cells are provided in 40 μL aliquots, sufficient for a single transformation. Transformation is performed by incubation on ice followed by heat shock at 42°C. Fo...
Keywords: Antibiotics, 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 agar plates for E. coli
CMR0001 Recovery Medium for Expression, for use with competent cells

Technical Service:

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