MultiShot StripWell BL21 Star (DE3) chemically competent E. coli cells are cloning competent cells that are packaged in a rack containing 12 strips of 8 wells to increase productivity for medium-throughput bacterial transformations. MultiShot StripWell BL21 Star (DE3) competent E. coli cells are designed for applications that require high-level expression of non-toxic recombinant proteins from low copy number, T7 promoter-based expression systems (e.g., Champion pET vectors). MultiShot StripWell BL21 Star (DE3) Competent Cells are provided at a transformation efficiency of 1 x 107
cfu/µg plasmid DNA.Enhanced expression of nontoxic recombinant proteins
MultiShot StripWell BL21 Star (DE3) Competent Cells contain the DE3 lysogen that carries the gene for T7 RNA polymerase under control of the lacUV5 promoter. IPTG is required to induce expression. This strain also offers enhanced mRNA stability due to a mutation in the RNaseE gene (rne131) that reduces levels of endogenous RNases and mRNA degradation, thereby increasing the stability of mRNA transcripts and increasing protein yield. Protein expression is further enhanced by the absence of the lon and outer membrane (OmpT) proteases, which reduces degradation of heterologous proteins.
Key features of the BL21 Star (DE3) Competent Cells include:
for promotion of high mRNA stability and protein yield
and lack of lon for minimal degradation of heterologous proteins by proteases
for use with low copy number, T7 promoter-based plasmids
It should be noted that BL21 Star strains have higher basal expression of heterologous genes than BL21 strains, due to the increased stability of mRNA. Therefore, these strains may not be useful for expression of toxic genes.MultiShot StripWell format—flexible for no waste
Each StripWell of eight connected tubes is designed with the same single-tube, single-use features as our One Shot format tubes. This format allows for all steps of the transformation protocol, up to plating, to take place in the same tube, thereby saving time and to preventing contamination. After addition of DNA, MultiShot StripWell chemically competent cells can be transformed by heat-shock at 42°C using a water bath, all in the same tube.
The StripWell tubes can be cut to permit transformations in a single tube, eliminating wasted aliquots of cells and avoiding freeze-thaws that can result in reduced transformation efficiency.
Key features of the MultiShot StripWell format include:
• Increase productivity
—for medium throughput experimentation
• Maximal flexibility
—transform as few as 1 tube and as many as 96 from the StripWell rack
• Familiar convenience
—no aliquotting, add DNA directly to cells, heat shock, and recover in the same tube
• Peace of mind
—single-use transformation minimizes contaminationGenotype:
F-ompT hsdSB (rB-, mB-) gal dcm rne131 (DE3)Find the strain and format that you need
We offer many other E. coli strains and formats of chemically competent cells
and electrocompetent cells
to help meet your specific transformation needs. If you require other high-throughput transformation options, choose from our collection of MultiShot formatted comp cells
or email us
for custom formatting options.
For Research Use Only. Not for use in diagnostic procedures.