[Histonet] Recommended thickness of Amyloid sections

[Bob Richmond]

In response to several questions and responses about amyloid staining:

I’ve always understood that sections for amyloid should be cut at 8 µm, but
could never get a histotech to cut them that thick.

I recall that unstained paraffin sections on the slide are usable for about
a month after cutting. That limitation precludes buying commercial controls.

Most (though not all) medullary carcinomas of the thyroid contain some
amyloid, and that’s about the only control you can get for yourself, and
it’s a rather rare tumor, and not easily recovered from a lab’s old records.

Every time somebody posts on amyloid on Histonet or elsewhere I’ve asked
this question, and never got the slightest reply: Amyloid (of the AL type,
I suppose) can rather easily be induced in experimental animals (by
injection of casein, for example). Does any pathology service use animal
material for amyloid controls? Is it commercially available?

In 2002 Dick Dapson at Anatech introduced “Amyloid Red” (Direct Red 72,
C.I. 29200) as a substitute for Congo red. I just checked the Web site and
Anatech still offers it. Does anyone have any experience with it?

Bob Richmond
Samurai Pathologist
Maryville TN