I still don't understand why a stain for copper is needed, unless to make a 
pretty photomicrograph for a conference. In iron staining, a negative iron 
stain (Perls prussian blue) makes quantitation unnecessary, but I doubt that 
a negative copper stain accomplishes the same thing. Here's current 
information on how to get the quantitative test done.

Mayo Medical Laboratories test 8687: copper, liver tissue. 
Paraffin block; requires 5 to 10 mm (2 mg) of needle biopsy liver tissue. 
Normal 10 to 35, primary biliary cirrhosis 40-80, early Wilson's disease 
100-300, late Wilson's disease >300 mcg/g dry weight. $130 in 2002. Done by 
inductively coupled plasma mass spectrometry, or ICPMS as those "in the loop" 
probably call it.

It would be difficult to find control material of human origin. Wilson's 
disease is rare, and the patient has usually (though not aways) been treated 
to remove the copper. Perhaps a recipient liver from a transplant for primary 
biliary cirrhosis would contain enough copper to be stainable, and would 
provide abundant control material.

I recall reading a good many years ago that positive control material can be 
prepared by feeding a rat chow laced with 0.5% copper acetate for six months, 
and staining sections of the liver. If the rat survives the experience till 
the fatal day.

Bob Richmond
Samurai Pathologist
Knoxville TN