ClearColi technology: ClearColi BL21(DE3) are ideal for the expression of low-endotoxin proteins. ClearColi BL21(DE3) cells have a modified LPS (Lipid IVA) that does not trigger the endotoxic response in mammalian cells. They lack outer membrane agonists for hTLR4/MD-2 activation; therefore, activation of hTLR4/MD-2 signalling by ClearColi is several orders of magnitude lower compared with E. coli wild-type cells, and heterologous proteins prepared from ClearColi are virtually free of endotoxic activity. After minimal purification from ClearColi cells, proteins or plasmids, which may still contain Lipid IVA, can still be used in most applications without eliciting an endotoxic response.

Routine cloning, low-endotoxin protein expression

• Genetically modified LPS-no endotoxin response in human cells
• Ideal for mammalian cell immunogenicity testing, toxicity assays, and therapeutic protein drug discovery
• Useful for membrane and lipid binding protein production
• Protein expression similar to BL21(DE3) cells without requiring downstream endotoxin removal

Transformation efficiency: ≥ 1 x 10⁹ (cfu/µg pUC DNA)

Genotype: ClearColi BL21(DE3): F– ompT hsdSB (rB- mB-) gal dcm lon λ(DE3 [lacI lacUV5-T7 gene 1 ind1 sam7 nin5]) msbA148 ΔgutQ ΔkdsD ΔlpxLΔlpxMΔpagPΔlpxP ΔeptA Seven specific deletion mutations (ΔgutQ ΔkdsD ΔlpxL ΔlpxMΔpagPΔlpxPΔeptA) encode the modification of LPS to Lipid IVA, while one additional compensating mutation (msbA148) enables the cells to maintain viability in the presence of the LPS precursor lipid IVA.

Components: ClearColi BL21(DE3) Electrocompetent Cell pUC 19 Trasformation Control Expression Recovery Medium (lactose minus)