------- Forwarded Message Follows -------

Reply-to:      ALLISON@CARDIFF.AC.UK
Date:          Fri, 27 Aug 1999 15:58:38 GMT0BST

PTAH has been discussed previously.  In my experience, the 
phosphotungstic acid was much mre problematic than the haematoxylin.  
Like it used to be said of stains and dyes, it's the impurities that 
make it work!!!
Russ Allison, Wales