[Histonet] Coagulants question

[Bob Richmond]

From: jdhannasch at gmail.com
To: histonet at lists.utsouthwestern.edu
Subject: [Histonet] Coagulants question
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"jdhannasch" (who) asks:

>>Can someone explain to me what a coagulant vs a noncoagulant is and why
it matters? I have never been able to really understand coagulants and why
they are important.<<

I suppose you're referring to fixatives. Coagulant fixatives make blood
clot, often because of their acidity. Neutral buffered formalin (NBF)
doesn't clot blood.

Back when I was doing bone marrow aspirations and biopsies in the 1970s,
I'd squirt some of the unclotted aspirate into NBF, and get small marrow
particles suspended in liquid with red blood cells. I'd filter out the
liquid part, then have the loose particles embedded. The rest I'd put in
Zenker/Helly fixative (those were the days, my friend!) where it would
promptly clot. I'd get the iron stain done on the particle suspension,
where the hemosiderin hadn't been leached out by the acid fixative or by
the decalcifier.

For further information, consult one of the textbooks like John Kiernan's.

Bob Richmond
Samurai Pathologist
Maryville TN