Phenol pH (was: RNA Extraction... ( Still ))

Cathy Sprankle Sprankle at
Sun Jun 30 20:40:59 EST 1996

In article <elauzier-2606961231340001 at>,
elauzier at (Edouard Lauzier) wrote:

> I was wondering if the pH of the phenol can affect the efficienty of the
> phenol/chloroform extraction...
> Then again, can I trust a pH measure where pH paper is wet with a drop of
> phenol who's so strong...
There are apparently a couple of different schools of thought as to how to
appropriately measure the pH of a phenol/chloroform solution (which is
what I assume you're using).  A couple of folks from Amresco published a
paper in Biotechniques (vol. 10, pp 740-741, 1991) describing their
recommended method, which involves measuring the pH of a solution of the
phenol/chloroform in methanol and water.  However, others I have talked to
say that dipping a piece of pH paper in the aqueous phase of your
buffer-saturated phenol/chloroform is sufficient.  Since I'm still
troubleshooting my current project, I have no firm opinion on the subject
:) !

Catherine Sprankle
e-mail:  sprankle at
Opinions expressed (such as they are!) are strictly mine and do
not reflect those of CIIT.

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