GELSHIFT HELP, No competition

Stephen R. Lasky Stephen_Lasky at
Sun Dec 3 12:13:26 EST 1995

In article <beavis-0212951411380001 at>,
beavis at (beavis) wrote:

> In article <30BD8A2C.58C9 at>, Eric Hanson
> <Eric.Hansson at> wrote:
> > Thanks,
> > 
> > Eric
> When I've done gel shift experiments with whole yeast cell extracts I will
> first add the "cold" competitor DNA to the reacation containing the yeast
> extract, incubate for 15 minutes--I then add the labeled DNA, incubate for
> an additional 15 minutes and then load the gel.
> jrs

JRS, this is not competition.  You have to add the competitor at the same
time as the labeled ligand (DNA) in order to have a truely competitive
system.   I have no answer to the original question, but if he did the
experiment this way, he would not be looking at competitive inhibition of
DNA binding.


Stephen R. Lasky Ph.D.   Brown U/Roger Williams Medical Center,  Providence, RI.   
Phone: 401-456-5672     Fax: 401-456-6569     e:mail: Stephen_Lasky at
America may be unique in being a country which has leapt from barbarism to decadence without touching civilization.  John O'Hara.

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