Carnoy vs MethCarn

From:Gayle Callis <uvsgc@montana.edu>

Carnoy contains ethanol, MethCarn methanol is used instead of ethanol.  For
fatty breast tissues, the chloroform would be removing the lipid component,
but is not a fixative per se.  Fixation occurs with alcohol (excessive
shrinkage if used alone) and acetic acid (excessive swelling if used alone)
so these two components offset these two disadvantages.  If we are not
working with fatty tissues, we leave the chloroform out due to its
toxicity/carcinogenicity.

These alcohol fixatives are wonderful with Factor VIII, clean, no
retrieval, fast!



At 09:47 AM 1/30/01 +0100, you wrote:
>Hi there,
>
>Although I am not experienced with breast tissue, we are dealing with
>similar "fatty problems" when handling atheresclerotic tissue specimens.
>When microwaving a formalin-fixed atherosclerotic tissue specimen the fatty
>plaque is sometimes gone as well as parts of the adventitia. The media
>stays nicely on the slide (unfortunately this is the most uninteresting
>part of tissue to us).
>
>I would like to bring in another fixative maybe worthwhile to test:
methacarn.
>It is composed of 6 parts methanol, 3 parts chloroform and 1 part acetic
>acid. Our Japanese collaboratorsin Osaka who came up with it even store
>whole hearts in methacarn!! When replacing methanol by alcohol it is named
>"Carnoy". I am not aware of any differences between methacarn and Carnoy.
>Since no formalin is involved, methacarn is a non-crosslinking fixative.
>Therefore, you do not need to microwave for immuno's. In our hands
>immunostaining (surfcace, cellular and nuclear markers) after
>methacarn-fixation is even somewhat stronger than after
>formalin-fixation/microwave treatment!!
>
>Have a happy staining-day using methacarn!!
>
>Chris van der Loos
>Dept of Cardiovascular Pathology
>Academical Medical Centre
>Amsterdam, The Netherlands
>
>
>
>
>
Gayle Callis
Veterinary Molecular Biology
Montana State University - Bozeman
Bozeman MT 59717-3610

406 994-6367
404 994-4303 (FAX)




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