Although you are probably cutting the sections at a supposed 8-10
     microns, your microtome may be off. The proper thickness is important
     to getting the right green color. We had the same problem with Congo
     Red and my solution was to cut slides varying from 7-10 and see which
     ones had better color. The greenest birefringent slides should be your
     new cutting thickness.                    jc


______________________________ Reply Separator
_________________________________
Subject: Congo Red Stain problems
Author:  "Jennings-Siena  Debbie" <ds.jennings-siena@baylordallas.edu> at
internet
Date:    01/13/2000 9:41 AM


  Hi everyone,
I would like to ask if anyone knows why amyloid on Congo Red stain would
birefringe as a orange-yellow color instead of apple green?  We are using
the same procedure that we have used for years.  Our procedure is a Puchtler
Modification.  If anyone has any ideas, I would appreciate hearing from you.
Thanks in advance.

Debbie J. Siena, HT(ASCP)QIHC
Histopathology Manager
Baylor University Medical Center
Dallas, TX 75246
214-820-2465