Antifoam in DNA isolation?

Savita Shah spshah at stanford.edu
Wed Sep 27 11:36:30 EST 2000


Hi there.. 
It may sound wierd.. but try this.. (talking about plant material
here)..
grind material in Liquid nitrogen, add pre-heated extraction buffer (I
have used buffers with CTAB, SDS or Sarkosyl.. works fine with all these
detergents)and continue grinding.. but then here is the trick.. keep
grinding in one direction without lifting pestle..that way you will
avoid foam formation and it will be much easier to scoop the mix. in the
eppendorf/tubes.. 

Grinding in Mortor helps a lot (than grinding in eppendorf..) as far as
the DNA amount/gm of tissue. It works fine with very little material
too.

Savita
P.S: After grinding I leave the sample in the mortor until it is
completely thawed (or until you finish this step with another sample..
personal experience). don't worry, thawing in mortor will not do any
harm to the DNA!

Dave Vadnais wrote:
> 
> Something we tried in our lab when we used the Fast-Prep Tissue grinder was
> to put the tubes on ice for 20 minutes after grinding.  I don't know what
> that would do to the SDS (probably cause it to precipitate), but it did
> reduce the foam in the mixture.  The DNA was subsequently used for PCR
> without any problems.
> 
> --
> Dave A. Vadnais
> Agriculture and Agri-Food Canada
> Southern Crop Protection & Food Research Centre
> 1391 Sandford Road
> London, ON
> N5V 4T3
> Phone: (519) 457-1470 (ext 694)
> Fax: (519) 457-3997
> e-mail: vadnaisd at em.agr.ca
> 
> "clarosa" <clarosa at biocomp.unl.edu> wrote in message
> news:39C10DE6.D570DE1D at biocomp.unl.edu...
> >
> >
> > Vince Mulholland wrote:
> >
> > > I want to use a mixer-mill to disrupt plant leaf material for DNA
> > > isolation. The lysis solution I want to use contains SDS, so will
> > > produce a lot of bubbles. If I can't minimise the formation of bubbles
> > > there will be a real risk of cross-contamination of the DNA (for use in
> > > PCR). Is there an antifoam which is compatible with most types of DNA
> > > isolation reagents?
> > >
> >
> > There was a recent thread where the purpose of isoamyl alcohol in
> > minipreps was discussed.   Reportedly, it was a antifoaming agent if I
> > recall correctly.  1 part in 25 is the amount used and I would assume it
> > to be compatable... perhaps a long shot. but adding the alcohol to your
> > buffer and doing the mixing can take what,, 2 minutes?
> >
> > >
> > > ---
> >






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