XL10 gold xells for protein expression?

Dr. Duncan Clark news at hgmp.mrc.ac.uk
Wed Jul 25 06:51:14 EST 2001


In article <3B5EF75E.25468.1029EF8 at localhost>, the eminent Wolfgang
Schechinger at messy. wrote
>Has anyone experience in XL10 (ultracompetent) e.coli for 
>protein expression? Wich expression systems (inducers) will 
>work? Strategene recommends BL21, but I don't want to buy 
>another strain.

What is your induction system, presumably not T7? I'd guess they are
suggesting BL21 because it is OmpT minus (outer membrane protease). If
you have BL21(DE3) then I can't see why that would not do. Granted you
will induce T7 RNA pol with IPTG from the DE3 lysogen bit but that may
not be a problem. Another reason for BL21 is that it is closer to a wild
type E.coli than a highly mutated XL10 and therefore will grow to
probably a much higher OD. Why not just try XL10 and see what happens. 

Ideally I would try every strain (within reason!) you have, providing
they meet your biological safety needs, and see which work best.  

Duncan  
-- 
The problem with the gene pool is that there is no lifeguard.

Duncan Clark
GeneSys Ltd.
Tel: +44(0)1252376288
FAX: +44(0)8701640382




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