How much ampicillin?

Brett Beitzel bbeitzel at
Mon Sep 23 13:26:27 EST 1996

I routinely use 50 ug/ml with no problems.  Higher concentrations may cut
down on satellite colonies, but I don't have much of a problem with them
at 50 ug/ml (although occasionally...)

Hope this helps,
Brett Beitzel
bbeitzel at

In article <526c64$8r1 at>, Bill Burnett
<bbur at> wrote:

> Promega recommend a final concentration of ampicillin in 
> LB/ampicillin/IPTG/X-gal plates (for E. coli JM 109 transformed with 
> T-vector) of 100 ug/ml...   Can I get away with only 50 ug/ml as 
> suggested by a lab manual or is this a false economy?
> Anyone got a sure fire cheap plate recipe?
> Thanks!!
> B.
> -------------------------------------------------------------------------
> Bill Burnett: bbur at            
> Scottish Association for Marine Science
> P.O. Box 3, Oban, Argyll, PA34 4AD.

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