Colour selection problem on XGal/IPTG plates

Martin Kennedy mkennedy at
Thu Dec 2 20:53:06 EST 1993

In article <2dkls2$2pu at>, osp086 at writes:

> DNA ligase. The products as well as uncut bluescript, bluescript cut +
> ligase and bluescript + no ligase (controls) were used to transform fresh
> competant E.coli XL1Blue. These were then plated on Luria agar plates
> containing ampicillin (50ug/ml) and XGal and IPTG at the levels stated in
> Maniatis. After growth for 24 hours the plates were transferred to a fridge
> to allow colour development. This however did not occur. The bacteria seem

> 		Craig Wilding.

Look at your bottle of Xgal, and make sure it is Xgal, not Xglu:i


and NOT 5-bromo-4-chloro-3-indolyl-B-D-glucopyranoside

cos the latter won't work!  



NNNN   NN  Martin A Kennedy (E-mail = mkennedy at  ZZZZZZZ  
NN NN  NN       Cytogenetic and Molecular Oncology Unit          ZZZ
NN  NN NN           Christchurch School of Medicine            ZZZ
NN   NNNN              Christchurch, New Zealand              ZZZZZZZ
	      Phone (64-3)364-0880  Fax (64-3)364-0750

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