Re: FW: Carnoy's (source of; why buy?)
<< Previous Message | Next Message >>
From: | "J. A. Kiernan" <jkiernan@julian.uwo.ca> (by way of histonet) |
To: | histonet <histonet@magicnet.net> |
Reply-To: | |
Content-Type: | text/plain; charset="us-ascii" |
On Tue, 10 Nov 1998, Luke, Don wrote:
> ... Who do you get the Carnoy's from? And, How much do you pay? I
> found 2 vendors Poly Scientific $94.00/gal and EK Industries $24.00/gal.
Why buy Carnoy's fluid ready-made? You can make
your own as needed by mixing the three cheap
ingredients. It takes less than 2 minutes, including
putting away the stock bottles.
If you do buy it ready made, it won't stay the same
as the fresh stuff. The reversible reaction:
acetic acid + ethanol <---> ethyl acetate + water
begins when the ingredients are mixed, and continues
over several days (longer?) until an equilibrium
mixture is attained. The fruity smell of ethyl
acetate is quite evident in Carnoy kept for 24-48
hours. I've never kept it for longer, and don't
know the composition of the final mixture, or
whether the chemical change makes any difference
to the fixation. However, the only way to be
sure you're using the same stuff every time is
to make it up fresh.
Interestingly, aged solutions of Gendre's "alcoholic
Bouin" (alcohol, acetic, picric & formalin) are better
than the freshly mixed fixative for some purposes.
An artificially aged mixture is made by including
25% ethyl acetate (Gregory RE 1980. Stain
Technol. 55: 151-160).
John A. Kiernan,
Department of Anatomy & Cell Biology,
The University of Western Ontario,
LONDON, Canada N6A 5C1
<< Previous Message | Next Message >>