Formaldehyde vs. Formamide for Northern

Ed Rybicki ed at
Thu May 4 04:53:11 EST 2000

"Kajetan H. Groicher" wrote:
> in article 3906AAFD.A180D195 at, Paul Klosen at
> klosen at wrote on 4/26/00 3:38 AM:
> > Vellanoweth's Lab wrote:
> >>
> >> We've been having a lot of trouble degrading our plant RNA with
> >> formaldehyde.  We've tried pHing the formaldehyde with NaOH to 5.3, and
> >> eliminating the formaldehyde from the incubation step.  

We have just had a journal club article which described running ordinary
TBE horizontal gels - DEPC-treated apparati and buffers - at 50 deg C,
with samples put in hot and fresh from a thermal denaturation in a
waterbath...with the current in the gel providing the heat!  Sounded
wonderful - will try to find ref if anyone interested.

PS: I have never run a formamide / glyoxal or other denaturing gel for
plant viral RNAs or DNA virus-derived mRNAs ever - and nor do my lab. 
We simply run 'em non-denaturing and avoid all of the problems - and
only lose a little info on absolute size, as most things run pretty near
their size anyway!

                     Ed Rybicki, PhD  
      Dept Microbiology     |   ed at   
   University of Cape Town  | rybicki at
   Private Bag, Rondebosch  |  phone: x27-21-650-3265
      7701, South Africa    |   fax: x27-21-689 7573
    WWW URL:      
       "Organised people just have limited horizons"

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