Problems with gel

mam7746 mam7746 at glaxowellcome.com
Wed Nov 17 23:24:04 EST 1999


Its been almost a month since your post, but I was wondering if you ever
got an answer.  

We were told by FMC to store our gel packs at room temp and never to freeze
them.  We had problems like you describe when we were storing them in the
refridgerator, and have not seen any problems since we began storing them
at room temp.  That would be my recommendation.  

Also, my understanding is that as formamide is exposed to air, it absorbs
water to create formic acid.  This acid will cause dye breakdown, resulting
in blue dye blobs and "shoulders". The best results would be obtained by 
making up loading dye fresh each day.  

Hope this information is helpful....

Michele Godlevski
Laboratory Supervisor
DNA Sequencing Facility 
Department of Genomic Sciences
Discovery Genetics Division
GlaxoWellcome, Inc.
% :  (919) 483-3801 

kris <krishna at mjr.com> wrote in article <7v55ud$9sl at net.bio.net>...
> Hi everybody,
> we are running long ranger gels in our lab at 5.25% with TBE, also
> degassing for 10 minutes, following the protocol completely, but our
> resolution lately for the last ten days has not been good at all. lanes
> are smeary, fading. we are also storing our premixes in the freezer and
> thawing it before we use it. also the thawed acrylamide is in the
> refrigeratot for a couple of days before we get to use it. we are also
> thawing the acrylamide right when we get it and aliquot it out. I am
> wondering if repeated thawing and freezing ( twice) causing a problem
> with our gels. Also does anyone know how long we can use the loading dye
> that is kept in the refrigerator, is there a break down time frame for
> dye and for acrylamide?
> any info will be very much appreciated.
> kris

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