EtOH + PBS = precipitation?

Jim Hutchins hutchins at
Sun Mar 3 10:44:17 EST 1996

LU Pin (bolupin at wrote:
: Recently when I tried to prepare 95% ethanol in PBS, I always got the 
: same problem. When PBS was added into abs. ethanol, the solution became 
: turbid. Later, some white precipitate formed. Shaking or vortexing during 
: PBS addition did not help. The PBS I used contains NaCl, KCl, Na2HPO4, 
: KH2PO4. Anyone knows what's wrong or how to avoid this? Thank you very much.

Why are you trying to prepare 95% EtOH/PBS?  As far as I'm aware, phosphate
precipitates under the conditions described.

If you tell us the intended use, maybe we can suggest a substitute.
Jim Hutchins
Assoc Prof Anatomy, Asst Prof Neurology (Research), Univ Mississippi Med Ctr    ***    E-mail:   hutchins at

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