Codon bias adjusted E. coli?

Chun-Song Yang yangcs at
Mon Feb 21 11:57:45 EST 2000

  I had tried Stratagene's BL21(DE3)-CodonPlus-RIL. In my case, the cDNA
contains several tandemly arranged (AGA)(AGG) rare codons. The cDNA can
hardly be expressed in BL21(DE3), that is, only seen from western blot.
But it got high expression in the "codonplus" cell.
  Hope that helps,

Codon Bias-Adjusted BL21 Derivatives for Protein Expression

Stratagene’s BL21-CodonPlus™-RIL competent cells provide high-level
expression of difficult-to-express heterologous proteins. These cells are
variants of Stratagene’s Epicurian Coli® BL21-Gold cells modified by adding
extra copies of the E. coli argU, ileY, and leuW tRNA genes to
overcome expression limitations in conventional E. coli hosts caused by
codon bias in the gene of interest. Two derivatives of
BL21-CodonPlus-RIL competent cells are now available for different levels of
expression control with T7 promoter-driven vectors, such as the
Affinity™ pCAL vectors and the pET vectors. The BL21-CodonPlus(DE3)-RIL
competent cells are an all-purpose strain for high-level protein
expression and easy induction with IPTG. When used with the CE6
bacteriophage, the BL21-CodonPlus-RIL cells provide exceptionally tight
control of protein expression, which is crucial in the case of extremely
toxic proteins. In addition, the basic BL21-CodonPlus-RIL competent cells
are excellent hosts for non-T7 RNA polymerase expression systems.

Paul Cullen wrote:

> Yes, but they're no good for brachy DNA
> > From: "Scott J. Coutts" <melias at>
> > Organization: Monash University
> > Reply-To: melias at
> > Newsgroups: bionet.molbio.methds-reagnts
> > Date: Wed, 16 Feb 2000 00:32:48 +1100
> > Subject: Codon bias adjusted E. coli?
> >
> > Hiya All,
> >
> > Does anyone know who sells codon bias adjusted E. coli strains?
> >
> > Thanks,
> >
> > --
> > --------------------------------+-------------------------------------
> > Scott J. Coutts                | Faculty of Medicine
> > scott.coutts at | Department of Microbiology
> > Phone: +61 3 9905 3872         | Wellington Rd. Clayton, Vic, 3168
> > --------------------------------+-------------------------------------

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