IPTG concentration for induction?

[Dr. Duncan Clark]

In article <deusebe-0910961556130001 at cherubin.ens.fr>, =?iso-8859-
1?q?Dani=E8le_EUSEBE?= <deusebe at wotan.ens.fr> writes
>   I have to induce beta-galactosidase in a liquid culture of E.coli Y1089
>lysogen for a lambda gt11 phage containing a beta-galactosidase-fusion
>protein gene.
>   I have read in a protocole to use 10 mM IPTG, which seems to me an
>enormous amount, since I have to make a liter scale culture.
>   Is this concentration required? What is the minimal efficient
>concentration to fully induce beta-galactosidase synthesis?
>

We routinely use 0.5mM final concn. for pUC derivative expression
vectors but we have gone down to 0.1mM on some.

10mM is way too much.

Duncan
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My mind's made up. Don't confuse me with the facts!
Duncan Clark
DNAmp Ltd.