What is 'gel mobility shift assay'?

[Dan Oerther]

In article <94311.215150VHWBC at CUNYVM.CUNY.EDU>, D. P. Wijesinghe
<VHWBC at CUNYVM.CUNY.EDU> wrote:

> Could someone please let me know what 'gel mobility shift assay' is?
>  
> Harshinee Wijesinghe

Dear Harshinee-
   A gel mobility shift assay, or gel shift, is used to determine
Protein/DNA interactions.  For example, one may synthesize an oligo with a
restriction factor binding site, mix protein + 32P labelled oligo, and run
on an acrylamide gel.  Once you have been able to shift a band, in future
experiments you can compete away signal by mixing the previously mentioned
"soup" with excess unlabelled oligo to prove Protein/DNA interaction via
competition.  Hope this helps.  Most, if not all, Molecular Biology
Protocol manuals will have a more complete description of the procedure.

Best,
Dan