electrophoresis of nuclear extracts

[Stephen R. Lasky, Ph.D. alt.binaries.pictures.erotica.blondes alt.binaries.pictures.erotica.d alt.binaries.pictures.erotica.female alt.binaries.pictures.erotica.male alt.binaries.pictures.erotica.orientals alt.binaries.pictures.fine-art.d alt]

In article <8NOV199414465358 at aardvark.ucs.uoknor.edu>,
mccarthy at aardvark.ucs.uoknor.edu (MC_CARTHY,DAVE) wrote:

>  We are trying to fractionate proteins in human nuclear extracts in SDS
>  polyacrylamide gels.  Althugh we observe sharp protein bands in 13%
>  polyacrylamide, we have problems with gels that are below 10%
>  polyacrylamide.  The protein forms vertical streaks along the edges of
>  the lanes.  Equivalent amounts of protein from E. coli extracts do not
>  show this sensitivity to polyacrylamide percentage in the same gels.
> 
>  Have others had this problem with nuclear extracts?  Are there any ways
>  to avoid this?  
> 
>  Thanks
>  Dave  
>

We commonly electorphorese our nuclear extracts on 10% gels and do not see
streaking.  Do you dialyze your extracts?  Most extracts are made with
high salts (0.42 M NaCl or some combination of NaCl and KCl) and this high
salt might cause streaking.  Not sure why the 13% gels doesn't show
streaking.

Hope that helps

SRL
PS: sorry if my organization line is very long, I can't figure out where
the list of alt binary usenet groups are coming from but we don't get most
of them at my site.

-- 
*********************************************************************Stephen R. Lasky, Ph.D.
Roger Williams Medical Center/Brown University
Phone: 401-456-6572       Fax: 401-456-6569       e-mail: Stephen_Lasky at brown.edu
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