Hi,

I was wondering if you have obtained your cell line? Because I am also looking for a cell line expressing T7.

E.coli BL21(DE3) is absolutely a good choice!

Hi Kavitha

T7 polymerase will transcribe any DNA linked to a T7 promoter. Hence, T7 expression systems can be developed in many types of cell provided that they are "DE3": they must carry the lambda DE3 lysogen. Lambda DE3 is a phage construct that expresses T7 RNA polymerase under the control of a lacUV5 promoter.

ref: Moffatt, BA et al. (1984) Nucleotide sequence of the gene for bacteriophage T7 RNA polymerase. J. Mol. Biol. 173 265-9

You can obtain a free sample of many cell lines from EdgeBio here (http://www.edgebio.com/request-quote) by selecting products, samples, and then the cell lines you wish to try. BL21 (DE3) ultra are a good choice and the gold standard here, but the Acella cell lines have the extra benefit of complete deletions of recA and endA genes. The deletion of these genes allows this cell line to be used like DH5-alpha cells for plasmid maintenance, propagation, and isolation.

Essentially, the Acella cells provide a single strain that works for plasmid isolation and protein production. There are also pLYsS carrying BL21 (DE3) strains that you could select if you fear your protein may be toxic to E. coli.

If you really wanted to, you could even make your own competent cells starting from the samples using this method. http://www.cshlpress.com/pdf/CondProt.pdf

If you do like the samples though, please spread the word. Best of luck! And no, if you're wondering, I don't work for EdgeBio, I just have had good luck with their products.