I think of all these picric-alcohol-formalin-acetic mixtures
as "alcoholic Bouin."  The idea of adding the acetic acid to the
stock solution immediately before using is probably to avoid the
slow reversible reaction with ethyl alcohol, which forms ethyl
acetate (fruity odour) and depletes the acetic acid. BUT for 
some purposes, especially insect histology, aged alcoholic Bouin
is claimed to be better than the fresh stuff. R.E.Gregory et al
published two thorough studies of this in 1980, in 
Stain Technology 55:143-148 and 55:151-160.  Gregory's optimal
fixative (which does not need to be aged) contains ethyl acetate.
-- 
-------------------------
John A. Kiernan
Department of Anatomy and Cell Biology
The University of Western Ontario
London,   Canada   N6A 5C1
   kiernan@uwo.ca
   http://publish.uwo.ca/~jkiernan/
------------
RSRICHMOND@aol.com wrote:
> 
> Tony Henwood has posted some information and a request for a reference
> concerning Brazil's fixative. I append his entire post below.
> 
> Eleven years ago I corresponded with Arthur H. Cohen, M.D. in the Department
> of Pathology, Division of Renal Pathology LAC-Harbor-UCLA Medical Center in
> Torrance CA, and I still have the correspondence on file. I asked him:
> 
> I just read your article "Frozen-section analysis of allograft renal biopsy
> specimens: reliable histopathologic data for rapid decision making" in Arch
> Pathol Lab Med  1991;115:386-389; April 1991. You refer to your article
> "Masson's trichrome stain in the evaluation of renal biopsies: an appraisal"
> in Am J Clin Pathol  1976;65:631-643 which apparently contains your formula
> for alcoholic Bouin's solution, in which you fixed renal biopsy specimens for
> at least an hour before frozen section.
> 
> He replied: I am enclosing the recipe for alcoholic Bouin's fixative which is
> also known as Dubosq-Brazil [Duboscq-Brazil] fixative. Stains commonly
> employed in renal pathology (Masson's trichrome, periodic acid-methenamine
> silver) come out especially well.
> 
> 80% ethanol 150 mL
> 37% formaldehyde    60 mL
> picric acid 1 g
> 
> Add 1 mL glacial acetic acid to 14 mL stock solution before use.
> 
> Leave in the fixative from 6 to 24 hours depending on the size of the tissue.
> Transfer to 70% alcohol to await processing for light microscopy.
> 
> Reference: Histopathology Laboratory Procedures, National Cancer Institute
> 
> Samurai pathologist's note: To avoid handling solid picric acid, since
> saturated aqueous picric acid contains about 21 g/L of picric acid, 30 mL of
> it would contain about 600 mg. If one amended this formula to:
> 
> saturated aqueous picric acid   30 mL
> absolute ethanol    120 mL
> 37% formaldehyde    60 mL
> 
> one would get a mixture that contained about 60% of the amount of picric acid
> present in the previous formula.
> 
> The only other reference that I [the Samurai Pathologist, that is] could
> locate was in The microtomist's vade-mecum (Bolles Lee): a handbook of the
> methods of animal and plant microscopic technique. 11th ed. Gatenby JB and
> Beams HW, eds. Blakiston, Philadelphia, 1950. p. 325. This venerable
> reference spell it Duboscq-Brazil.
> 
> Bob Richmond
> Samurai Pathologist
> Knoxville TN
> ***************
> My laboratory has used a fixative called BRAZIL'S FLUID for fixing tissues
> where small amounts of glycogen are being sought. It is supposedly a good
> fixative for glycogen. Unfortunately I have no reference for this fixative
> nor its uses. The formula is as follows:
> 
> Absolute alcohol    1650ml
> Formalin    600ml
> Trichloracetic acid     7.5g
> Picric acid     10g
> Dissolve picric acid, then Trichloracetic acid in the alcohol, then add the
> formalin.
> 
> Fixation time:-
> Normal block size 3-4 mm thick  24 hours
> Needle biopsy   3-4 hours
> 
> The only one I know of is Dubosq-Brasil fluid which is similar (an alcoholic
> Bouin's fluid):
> 
> ethyl alcohol 80%    150ml
> picric acid         1g
> immediately before use add:
> Formol 35%           60ml
> acetic acid, pure    15ml.
> 
> From: Bock, P.: "Romeis Mikroskopische Technik", 17th. ed., p. 98.
> 
> Would anyone have a reference for BRAZIL'S FLUID that they could share with
> me?
> 
> Thanks muchly,
> 
> Tony Henwood JP, BappSc, GradDipSysAnalys, CT(ASC)
> Laboratory Manager
> The Children's Hospital at  Westmead,
> Locked Bag 4001, Westmead, 2145, AUSTRALIA.
> Tel: (02) 9845 3306
> Fax: (02) 9845 3318
> 
> http://www.histosearch.com/homepages/TonyHenwood/default.html
> http://us.geocities.com/tonyhenwoodau/index.html
_______________________________________________________