Function of octanol/isoamylalcohol?

Bernard Murray, PhD spam at
Tue Aug 1 22:01:59 EST 2000

In article <3986CFF8.736090AA at>, Chris LaRosa
<clarosa at> wrote:
> You mean to the phenol??? Isoamyl alcohol changes the density or
> partitioning behavior of the organic phase, so that it centrifuges to
> the bottom of the tube and the aqueous phase remains on the top. 
> Otherwise, classic phenol/chloroform partitioning would be a hassle as
> the organic phase would be on top.

Physics must work a little differently in your part of the country.
The density of phenol is about 1.07 so it will always be on the
bottom of a water/phenol mix.  I've heard the isoamyl alcohol usage
explained as an anti-frothing agent and also as something to
inhibit adsorption of material (i.e. nucleic acids) to glass
(from back in the stone age when Corex tubes roamed the earth).


Bernard P. Murray, PhD
bpmurray at cgl . ucsf . edu
Department of Cellular & Molecular Pharmacology, UCSF

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