Help! Problem with Northern Blots!

Pamela Norton pnorton at lac.jci.tju.edu
Fri Apr 11 13:03:36 EST 1997


In article <Pine.SUN.3.95q.970409145222.15696A-100000 at ganymede.cs.mun.ca>,
Joy Buckle <jbuckle at cs.mun.ca> wrote:

> I have been carrying out Northern blots for the last six months and the
> lab tech here has been doing them for 2 or 3 years.  Things up until now
> were fine but in the last month or so we have been producing blots that
> are literally half black (full of radioactivity) and half normal. For
> example, today I developed a membrane from a large gel.  The bottom lanes
> were perfect but the top half was simply black.  It was impossible to even
> determine where the lanes were. This is why it is so puzzling.  We are

Description of hybridization conditions omitted..

Joy,

     I have seen exactly this before on a Southern blot when I had reused
the electrophoresis tray buffer. The DNA migrates into the the top of the
gel uniformly across the entire gel. If you haven't reused the buffer in
your case, I might suspect that the apparatus is somehow contaminated with
plasmid DNA. Trying cleaning everything thoroughly and making fresh buffer.


     Hope this helps, and good luck,

          Pam Norton

-- 
Pamela A. Norton, Ph.D.          Associate Professor of Medicine
Thomas Jefferson University
Philadelphia, PA 19107           p_norton at lac.jci.tju.edu



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