How much ampicillin?

[Bill Burnett]

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.

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Bill Burnett: bbur at dml.ac.uk            
Scottish Association for Marine Science
P.O. Box 3, Oban, Argyll, PA34 4AD.