Function of octanol/isoamylalcohol?

Malay curiouser at
Thu Aug 3 13:03:49 EST 2000

> Chris LaRosa 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.
> Are you aure?  My memory of phenol/chloroform extractions during
> minipreps (without any isoamyl alcohol added) is that the aqueous phase
> is on top.
> Yep.  Just checked my old protocol.  No isoamyl alcohol, aqueous phase
> on top.

I have been using phenol/chloroform without isomamyl alcohol for the last 7
years. Never noticed any problem. I guess isoamyl alcohol is just another
lab-legends like cold ethanol for DNA precipitation.



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