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Competent cells for difficult or toxic protein expression

The OverExpress™ C41(DE3) and C43(DE3) competent cells from Lucigen enable researchers to express a wider variety of targets, including toxic or difficult proteins (e.g. membrane proteins), in one easy-to-use E. coli expression system. Offering high protein yields, these cells stabilise toxic plasmids to increase the amount of soluble protein expressed, with no need to re-clone and optimise alternate systems.

Benefits of using OverExpress competent cells
• High transformation efficiency
• Ideal for expression of toxic or difficult (e.g. membrane) proteins
• Stabilises toxic plasmids to increase protein yield
• Wider variety of targets can be expressed
• Easy-to-use expression system
• Well-cited for use in expressing a wide variety of proteins
• Available in electro or chemically competent format
• For use with T7 promotor containing plasmids

Format Name Efficiency Catalogue numbers

Electrocompetent

OverExpress C41(DE3) electrocompetent cells  ≥1 x 1010 cfu/µg pUC19 60341-1
60341-2
OverExpress C43(DE3) electrocompetent cells ≥1 x 1010 cfu/µg pUC19 60345-1
60345-2
Chemically competent OverExpress C41(DE3) chemically competent cells ≥1 x 106 cfu/µg pUC19 60442-1
60442-2
OverExpress C41(DE3) pLysS chemically competent cells ≥1 x 106 cfu/µg pUC19 60444-1
60444-2
OverExpress C43(DE3) chemically competent cells ≥1 x 106 cfu/µg pUC19 60446-1
60446-2
OverExpress C43(DE3) pLysS chemically competent cells ≥1 x 106 cfu/µg pUC19 60448-1
60448-2
OverExpress ChemComboPack (3 reactions each of 4 chemically competent strains) ≥1 x 106 cfu/µg pUC19 60452-1


OverExpress competent cells express toxic proteins better than standard BL21(DE3) cells

OverExpress competent cells express toxic proteins better than standard BL21(DE3) cells

Green Fluorescent Protein (left) or Red Fluorescent Protein (right) expressed from a T7 promotor construct that was transformed into C41, BL21 or C43 competent cells, spread on IPTG plates to induce protein expression.

OverExpress C41(DE3) and C43(DE3) strains are superior to the parental BL21(DE3) in transformation and expression of toxic proteins

OverExpress strains are superior to parental BL21(DE3) strain in transformation and expression of toxic proteins

Comparison of OverExpress C41(DE3) and C43(DE3) cells with the parental strain BL21(DE3) in transformation and expression of heterologous proteins. 
L. Dumon-Seignovert, G. Cariot, and L. Vuillard (2004). Protein Expression and Purification 37, 203-206. Data used with permission.

Material available for download
OverExpress Electrocompetent cells manual
OverExpress Chemically competent cells manual

Applications
• Membrane protein expression in E. coli
• Toxic protein expression in E. coli
• For use with T7 promotor containing plasmids

OverExpress competent cells citations

Products

Note: product availability depends on country - see product detail page.

Details Cat number & supplier Size Price
OverExpress ChemComboPack 60452-1 · Lucigen
60452-1
Lucigen
12 reactions (solos) £312.00
12 reactions (solos)
view
OverExpress C41(DE3) Electrocompetent Cells 60341-1 · Lucigen
60341-1
Lucigen
12 reactions (solos) £376.00
12 reactions (solos)
view
OverExpress C43(DE3) Electrocompetent Cells 60345-1 · Lucigen
60345-1
Lucigen
12 reactions (solos) £376.00
12 reactions (solos)
view
OverExpress C41(DE3) Chem Comp Cells 60442-1 · Lucigen
60442-1
Lucigen
12 reactions (solos) £312.00
12 reactions (solos)
view
OverExpress C41(DE3) pLysS Chem Comp Cells 60444-1 · Lucigen
60444-1
Lucigen
12 reactions (solos) £312.00
12 reactions (solos)
view
OverExpress C43(DE3) Chem Comp Cells 60446-1 · Lucigen
60446-1
Lucigen
12 reactions (solos) £312.00
12 reactions (solos)
view
OverExpress C43(DE3) pLysS Chem Comp Cells 60448-1 · Lucigen
60448-1
Lucigen
12 reactions (solos) £312.00
12 reactions (solos)
view