ClearColi BL21(DE3) Electrocompetent Cells (DUOS) > 1 x 10e9 cfu/ug

Product Description

• Genetically modified LPS does not trigger endotoxic response in human cells
• Ideal for mammalian cell immunogenicity and toxicity assays
• Reduce false positives in cytokine assays, improve confidence in your results
• Applications: Protein Production, Plasmid Production and Phage Display applications

ClearColi™ BL21(DE3) cells are the first commercially available competent cells with a modified LPS (Lipid IV_A) that does not trigger the endotoxic response in human cells. 

Figure 1. LPS vs. lipid IV_A structure comparison.
The LPS of normal E. coli cells compared to the genetically modified lipid IV_A from ClearColi cells. In ClearColi cells, the oligosaccharide chain is deleted, and two of the six acyl chains are removed to disable the endotoxin signal.

Fig.2. Endotoxicity of Protein from ClearColi™ BL21(DE3) vs. Standard BL21(DE3).
Comparison of endotoxic response from protein derived from ClearColi BL21(DE3) and traditional BL21(DE3) competent cells. ApoA1 protein was expressed from a T7-promoter based plasmid in both cell types, followed by a simple Ni-column purification step and without any subsequent endotoxin removal steps. The purified proteins were then tested for Toll-like receptor (TLR) stimulation by assessing NF-κB activation in HEK293 cells expressing human TLR4. Protein derived from ClearColi BL21(DE3) cells demonstrated no activation at concentrations five orders of magnitude greater than the protein from traditional BL21(DE3) cells.

Features

Transformation efficiency: ≥ 1 x 10⁹ cfu/µg pUC19*

(* As a control for transformation, ClearColi Electrocompetent Cells are provided with supercoiled pUC19 DNA at a concentration of 10 pg/μl. Use 1 μl for transformation.)

Genotype

F^-ompT hsdSB (rB- mB-) gal dcm lon λ(DE3 [lacI lacUV5-T7 gene 1 ind1 sam7 nin5]) msbA148 ΔgutQΔkdsD ΔlpxLΔlpxMΔpagPΔlpxPΔeptA

Limited Use Label License

There's a Limited Use Label License for ClearColi™ System (see User Manual for details).