Water as Buffer? was "Oligo stability..."

Hiranya Roychowdhury hroychow at NMSU.EDU
Wed Aug 12 12:40:17 EST 1998

At 11:05 AM 8/12/98 +0100, Richard P. Grant wrote:

>Pure water is pH 7.0 by definition.   (Equal concentration of H+ and
>OH-).  If your pH meter reads 6, then it is the pH meter that is failing,
>not necessarily the water.  And I will add that most pH meters cannot give
>a precise reading in such weakly buffered conditions, so do not feel that
>you have an inferior product!
>Richard P. Grant MA DPhil     |             rgrant at cmtech.co.uk
>Senior R&D Scientist          |             work: www.cmtech.co.uk
>Cambridge Molecular           |      home: www.avnet.co.uk/adastra           
>             -- Standard corporate disclaimers apply --

        Yes, indeed H2O should have a pH of 7 by definition. We are not
dealing with H2O, but with Water (most labs are) that, most of the time is
pumped out from some underground source, deionized and then either distilled
or further deionized and filtered through something like a Millipore system
before being deemed fit for any laboratory work.

        The second contention is a bit shaky... By definition, H2O is no
"buffer", weak or otherwise.



Dr. Hiranya Sankar Roychowdhury
Plant Genetic Engineering Lab.
New Mexico State University
Las Cruces, NM 88003
Ph. (505) 646-5785
hroychow at nmsu.edu

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