Are we talking about Cryotococcus neoformens or Crytosporidia in the orginal
question?

My answer was for the parasite and not the fungus.

If I were doing the fungus, GMS and mucicarmine would be a choice.  The
Grocotts would be using chromic acid and not periodic acid (see the latest
J Histotechnology, June 1999, for a very profound and excellent article
on using periodic acid for fungus, Histoplasma). 

I am suddenly seeing some different answers to this "cryptic" question.

Gayle Callis