Carmen,

One publication that would be worth your while to read as you prepare for 
the exam is the AFIP staining manual.  In there you will find methods to 
remove many pigment types, formalin pigment being one of them.  The method 
I use is ammonium hydroxide in ethanol.  Add 15 mL of 28% ammonium 
hydroxide to 50 mL of 95% ethanol. Decerate the slides as usual then place 
in the above solution for 1 hour.  Wash well in tap water.  I have used 
this before histochemical and immunohistochemical procedures with success.

Rob

Robert S. Geske
Research Associate
Center for Comparative Medicine and Department of Pediatrics
Baylor College of Medicine

-----Original Message-----
From:	Badley, Carmen M SrA LRMC [SMTP:Carmen.Badley@lnd.amedd.army.mil]
Sent:	Monday, October 25, 1999 2:07 AM
To:	'histonet@pathology.swmed.edu'
Subject:	formalin pigment removal

I am currently working on my certification (HT) and have ran into a 
problem.
I am performing an iron stain on spleen that is full of formalin pigment. 
 I
do not have picric acid to remove the formalin pigment so I tried Bouin's,
which worked great.  The only problem is that the glacial acetic acid is
wiping out the iron.  Does anyone have any suggestions to help me save the
iron while removing the formalin pigment???  thank you!