smear on PCR gels

Martin.Gossen at Martin.Gossen at
Tue Sep 27 17:34:53 EST 1994

> I am going crazy with smears on my PCR gels.  Using the same set of
> primers, sometimes I get very nice product band(s), but sometimes I
> get a diffuse smear from top to bottom with no bands.  Any hints as
> to what may be going on to cause this?  Thanks--
> Frederick C. Garbrecht
> fred at
> Bone Marrow Transplant Program
> Medical College of Wisconsin
> phone 414 257 5053
> fax   414 257 7994

I found that the gel running conditions can be very critical as well;
especially the running temperature was of great importance when I run
PCR products on a denaturing polyacrylamid gel. Best results were obtained
at 49 deg C but the amount of smear still depended on the location on the
gel (most smear in the middle), so it seems one has to find his own
optimum temperature for his special gel running system.

Martin Gossen
Dept. of human molecular genetics
Ruhr-Universitaet Bochum
martin.gossen at

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