reusing agarose gels

Paul St. Amand pst at
Wed Jun 15 13:39:47 EST 1994

In article <s.d.huen-150694120501 at>, s.d.huen at
(David Huen) wrote:

> In article <2tk8sp$asl at>,
> dsammata at (Diana Sammataro) wrote:
> > 
> <stuff deleted>
> > 
> >      1.Can I reuse agarose gels, and what happens to DNA and EB in the
> >      gels.
> Yes, just melt it down (+ wee bit of water) and recast it. Both are still
> there. The next time round, you will not need to stain the gel as the EB is
> still there. Boiling denatures DNA and ssDNA doesn't fluoresce as much with
> EB. Still, the background rises with increasing recycling (some bits of
> dirt will also fluoresce...). I've done 4-5x recycling out of sheer sloth
> before...

We simply run the DNA off of the gel (by electrophoresis) after
photographing. The gel can then be reused without melting and recasting. We
add EtBr to the buffer or add it to the wells with the sample. This is
great for those expensive 4% agarose gels. If your application doesn't have
too many bands, you don't even need to run the old DNA off the gel. Just
make sure that new bands aren't migrating over old ones. I have reused a
gel this way at least 5 times and it seems like it can take many more runs.
The only trouble is with low % agarose (0.6 to 1.5 %) gels, they tear
easily with the repeated handling.

Paul C. St. Amand                                    Research Geneticist
USDA/ARS and KSU Agronomy Dept.                      PST at KSU.KSU.Edu
(913) 532-6168                                       Fax (913) 532-5692

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