blue/white selection problem

Chris LaRosa clarosa at
Mon May 15 16:13:05 EST 2000

Perhaps dephosphorylation is not efficiently done.   Run minus insert
but dephosphorylated vector control and compare.   You say no inserts so
concatenation is likely the problem.   For CIAP the manufacturers
specify 50 C treatment for 5 prime recessed ends and 37 for 5 prime
overhangs, I suppose because the enzyme works on single strand version
and 50 degree opens the end enough to allow the enzyme acess.  

Rodney Earl Pettway wrote:
> I am using blue/white selection to choose colonies with my insert.
> Unfortunately, my white colonies don't have inserts.  What could be
> causing this.
> Rodney Earl Pettway
> USDA-ARS Cereal Disease Lab
> University of Minnesota
> St. Paul, MN., 55108

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