[Histonet] Re: Unencased Amoeba Stain

[Bob Richmond]

Matt Brooks asks: >>One of our Neuropath docs is inquiring about a
special stain for unencased
[amoebae] in cornea biopsies. I did a search and Gridley's method was
the best option that appreaded [sic]. Is there someone that could
either verify this stain will work on this organism or let me know
what you stain you are using?<< and René Buesa suggests Heidenhain's
iron hematoxylin.

Corneal ulcers are caused by Acanthamoeba and related species, rather
than by Entamoeba histolytica. Google >>amoeba corneal stain<< - some
references suggest a fluorescent stain such as calcofluor white, if
you have access to a fluorescence microscope.

Iron hematoxylins provide exquisite nuclear detail, but are
challenging to set up for the first time (I've done it), and are not
specific.

Periodic acid Schiff (PAS) is often used to demonstrate the glycogen
in Entamoeba histolytica trophozoites, but I don't know if the other
pathogenic amoebae contain glycogen.

My advice would be to ask one of the academic eye pathologists. My
choice would be Dr. Hans Grossniklaus at Emory, but there are a good
many more. And remember you'll need to find a control slide.

Bob Richmond
Samurai Pathologist
Maryville TN