[Histonet] Microwave processing

John Kiernan jkiernan <@t> uwo.ca
Sat Jul 14 23:33:31 CDT 2007

Do the makers say what else is in their "ethanol based fixative", and do they cite peer-reviewed literature to support their "All clinical trials ..." claims? 
There is a large body of peer-reviewed scientific literature concerning fixatives that are mostly alcohol (methanol or ethanol) mixed with other liquids, notably water, acetic acid, chloroform and xylene. As coagulants of protein and DNA, these fixatives avert the antigen masking caused by aqueous formaldehyde. 
Alcohol alone is OK for fixing smaears or monolayer cell cultures, but it's no good for bits of tissue. Additives, notably acetic acid, allow ethanol and methanol to fix larger chunks of  animal and plant organs. This stuff is all in the books. Any textbook published since about 1900 should be almost up to date on the physics and chemistry of fixation by non-aqueous liquids. Every  histotechnical book published since 1950 contains many alcohol-acetic fixatives. It is argued that methanol is superior to ethanol, and the "methacarn" mixture (Carnoy's fluid with methanol replacing ethanol) has been thoroughly studied. It's important use it correctly, and not to pass the fixed tissue through any solvent mixture containing water. See H. Puchtler et al. (1970) Histochemie 21:97-116. Not following the corect procedure can make tissues unduly shrunken and tough to section.
John Kiernan
Anatomy, UWO
London, Canada
 ----- Original Message -----
From: Garth Jerome <garth <@t> apollosci.co.za>
Date: Friday, July 13, 2007 21:49
Subject: RE: [Histonet] Microwave processing
To: histonet <@t> lists.utsouthwestern.edu

> Hello
> Milestone s.r.l produce a 'proprietary' fixative called FineFix. 
> This is an
> ethanol based fixative. All clinical trials of this reagent have 
> shown that
> it produces equal to or better IHC results than formalin fixed 
> tissues.
> We use it occasionally for microwave enhanced fixation of fresh 
> tissues and
> gross hardening of organs. It works beautifully!
> No IHC problems here.
> Regards
> Garth Jerome
> Apollo Scientific cc
> Telephone : 27-11-466 7666
> Fascimile : 27-11-466 7672
> Email : garth <@t> apollosci.co.za

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