DNA extraction from gel

Rick Bright rbright at rmy.emory.edu
Sat Aug 28 15:16:41 EST 1999

GeneClean Spin does not use NaI at all.

Anne Gillen wrote:
> > There are kits by Qiagen, Bio101 and probably by many other companies. These
> > I know are based on gel solubilization by NaI. High salt concentration make
> > DNA bound to silica gel (silica particles, silica membrane or whatever),
> > then washing the resin with alcohol and elution with water. These methods
> > work well as RNA/DNA extraction methods too if you substitute NaI with
> > GuSCN.
> >
> > Cheers,
> > Tomek
> Tomek,
> I know this may sound like nit picking, but I once had someone tell me in all
> seriousness that you did not need NaI to use the gene clean on PCR fragments
> (Sometimes I use the kit to clean up PCR, not bands in agarose) because it is
> only needed to solubilize the agarose.  This is not so.  I looked up the
> original paper and it said that NaI, or other chaotropic ions, are needed to
> bind DNA to the silica.  Once the DNA is bound you no longer need the NaI to
> maintain the bond.
> Anne

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