Mobility Shift and Glutamic Acid

Ken Doyle kdoyle at promega.com
Tue Mar 7 15:27:09 EST 1995


stefan at resunix.ri.sickkids.on.ca (Stefan Einar Stefansson) wrote:
>
> 
> Hi
> 
> I am currently doing mobility shift on purified transcriptional
> factor. By substituting the potassium chloride for potassium
> glutamic acid, I can get much stronger shift. Unfortunately,
> the free probe, barely separates from the one being shifted,
> when run on the gel.
> 
> Has anyone encountered this problem, and/or knows how to get
> a better separation, of the free probe from the shifted complex?
> 
> Hope to hear from as many as possible,
> 
> Stefan
> stefan at sickkids.on.ca


The separation is dependent on a lot of factors: could you provide
more information such as -

the size of the probe and factor
the % gel being used
gel running buffer
voltage gradient used

If you are shifting a relatively small factor (<10 kD) with a small 
probe (<20 bp) then you will need to optimize all these factors to 
obtain the best separation.

Ken
kdoyle at promega.com


***Opinions are my own, and not my employer's, etc.***



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