Blue colonies

Dr. Duncan Clark duncan at
Tue Apr 22 09:36:24 EST 1997

In article <335C20DA.5440 at>, Zhiyong Zhao
<zxz4 at PSUVM.PSU.EDU> writes
>Hi, Rodney:
>Did you accidentally plate the cells on the plates containing X-gal and 
>IPTG? DH5 has a whole LacZ gene.

You don't need IPTG with DH5alpha and a pUC plasmid. The strain is lacI-
so lacZ is switched on continuously. Xgal plates alone would give blue

The problem with being on the cutting edge is that you occasionally get 
sliced from time to time....

Duncan Clark
DNAmp Ltd.
TEl/FAX 01252376288

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