We have done Gomori's iron stain for many, many years without a problem....
until now....

Suddenly and for no apparent reason, it just stopped working.  No nothing.
Have run a dozen different controls,  changed reagents, made up new
reagents, changed to high purity water....

Has this happened to anyone else?  It's such a simple stain.  I would
appreciate any thoughts you might have. 

Tom Mc Nemar
Pathology Supervisor
Licking Memorial Hospital
Newark, Ohio