dear all

A 4% paraform./PBS prep has gotten out of hand.  The paraformalin will not
go into solution.  The pH is at least 10 (by ph paper).  Temp. is 65
deg. C.

I decided to use NaOH pellets this time.  I don't know why.  Normally, I
use 10 N NaOH.  Never have I seen this problem.

Any ideas?

Does anyone know at what pH paraformalin goes into solution at between 60
and 70 deg. C?

As always, thanks for the help.

John Carroll Dennis
Anatomy, Physiology, and Pharmacology
109 Greene Hall
Auburn University, AL  36849