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CMC0016

Sigma-Aldrich

BL21(DE3) Electrocompetent Cells

Escherichia coli, rod shaped

Synonym(s):

BL21 strain

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About This Item

UNSPSC Code:
41106202
NACRES:
NA.85

product name

BL21(DE3) Electrocompetent Cells, for protein expression

biological source

Escherichia coli

grade

for molecular biology

growth mode

adherent or suspension

morphology

rod shaped

technique(s)

microbiological culture: suitable

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.

Genotype

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

Components

  • BL21(DE3) electrocompetent cells
  • pUC 19 transformation control DNA
  • recovery medium for expression


Storage Class

10 - Combustible liquids

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

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Julianne M Troiano et al.
eLife, 10 (2021-01-16)
Under high light, oxygenic photosynthetic organisms avoid photodamage by thermally dissipating absorbed energy, which is called nonphotochemical quenching. In green algae, a chlorophyll and carotenoid-binding protein, light-harvesting complex stress-related (LHCSR3), detects excess energy via a pH drop and serves as
Felix Nicolaus et al.
eLife, 10 (2021-02-09)
We follow the cotranslational biosynthesis of three multispanning Escherichia coli inner membrane proteins in vivo using high-resolution force profile analysis. The force profiles show that the nascent chain is subjected to rapidly varying pulling forces during translation and reveal unexpected
Salvatore Di Girolamo et al.
Microbial cell factories, 19(1), 170-170 (2020-08-29)
Miniaturization of biochemical reaction volumes within artificial microcompartments has been the key driver for directed evolution of several catalysts in the past two decades. Typically, single cells are co-compartmentalized within water-in-oil emulsion droplets with a fluorogenic substrate whose conversion allows

Articles

Bacterial Transformation

Bacterial transformation is a process of horizontal gene transfer by which some bacteria take up foreign genetic material (naked DNA) from the environment. Bacteria that can take up free, extracellular genetic material are known as competent cells.

Protocols

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 the table below. Note that alternate settings result in transformation efficienes about 20-50% lower. Typical time constants are 3.5 to 4.5 msec.

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