SAP degrades my vector

[James Gray]

	I have recently encountered problems using USB's Shrimp Alkaline 
Phosphatase (SAP).  On two occasions dephosphorylating NotI digested 
pBluescript I've noted the SAP enzyme to degrade the vector.  I'm using 
overnight incubation at 37C to ensure a complete reaction.  I've spoken  
with a couple of other people who've had similar problems with this  
enzyme.  It is quite possible that these people had enzyme from the  
same lot as I, #85686.  To make matters worse the resulting degraded 
products have compatible-ends and can re-ligate.  Has anyone else had this 
problem?  If you do use this enzyme I'd recommend gel purifying the 
reaction product and definitely running a vector self-ligation control 
with each batch.

Thanks for any info!


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James P. Gray                        ___|___   
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