[Histonet] formalin substitutes. HELP

Rene J Buesa rjbuesa <@t> yahoo.com
Fri Nov 9 08:24:58 CST 2012

NO formalin substitute will work in the same way as formalin and the solution is not to start testing other "substitutes" that will make your life miserable and your sections and staining procedures of sub-standard quality.
The solution is:
1- to use LESS amounts of formalin (a 5:1 volume is more than enough);
2- have a well ventilated area;
3- do NOT prepare your own buffered formalin; buy pre-filled sample bottles; and
4- never handle formalin more than absolutely necessary.
Under separate cover I am sending you 2 articles I wrote on this subject
René J.

From: Nieves Gomez <ngomez <@t> neiker.net>
To: histonet <@t> lists.utsouthwestern.edu 
Sent: Friday, November 9, 2012 8:55 AM
Subject: [Histonet] formalin substitutes. HELP

Dear Histonetters,

I'm new in the net. I work as Pathologist in a Vet Lab in Spain.

Because formalin is toxic our Lab is for the practice of using
alternative fixatives. I think the main viable alternative is glyoxal
based formulas, but I have so many questions that Commercials don't know
or don't want to answer me. For example, have a MSDS or is it
accessible? Really is less hazardous than formalin or just is not
checked? (the advantages and desadvantages of formalin are known for at
least 100 years). Related to this, I think the glyoxal is suggested as a
formalin substitute in an article in 1940's and now it is sold as a "new
product" and most of the products are sold as "green", "no-toxic" or
"non harmful". In my opinion, a fixative can not be "non-toxic" if you
want it fixed tissues. 

Another question is the time needed to fix tissues or the ratio volume
specimen/fixative. To the first point, I have read an article that
mentions there is mould growth in specimens over time. Are we changing a
"chemical risk" to a "biological risk"? In my lab we have a specifically
workstation for the gross examination and sectioning of specimens, and
we wear all the Personal Protective Equipment needed (formalin chemical
filters, gloves, googles...) that minimizes the risk (the chemical risk
not the biological risk).  It is believed that formalin given time will
kill any microorganisms (or spores) present in tissues, mycobacteria
also.. what about these new products? Are they germicidal?

I do not get to appreciate the morfological changes (nuclear changes,
lysis of erithrocites, eosinophilia...) because they are well
documented. My aim is to know if there is any Lab that works with any
formalin substitute routinely to aks these questions. Please, help me.

Thanks and have a nice weekend

Nieves Gomez
Veterinary Pathologist
Animal Health Department
Berreaga, 1.
48160 Derio. Bizkaia. Spain.
ngomez <@t> neiker.net

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