[Histonet] aldehyde fuchsin

Wed Aug 17 11:36:17 CDT 2005

This is the method in M. Gabe's "Histological Techniques"
(1976); it's also in my textbook. A similar method
was published by Rosa,CC 1953 Stain Technol. 28:299-302.
For comparisons of aldehyde fuchsine made in different 
ways, see papers by GW Nettleton in J. Histochem.
Cytochem. 1980-1982.

Dissolve 1 g pararosaniline (CI 42500) in 200 ml water. 
Heat to boiling and leave to cool to room temperature.
Add 2.0 ml concentrated hydrochloric acid.
Add 1 ml paraldehyde.
Leave for 24 hours (longer if a pink ring
appears when a drop of the solution is spotted 
onto filter paper).
Filter and discard the filtrate.
Wash the residue with 50 ml water, then
dry the filter paper and its contents in
ab oven at 60C. Collect the dry aldehyde
fuchsine powder in a little screw-cap
bottle.

The dye must be pararosaniline (CI 42500).
The other components of basic fuchsine are
not suitable for this stain. You can use
acetaldehyde instead of its cyclic trimer, 
paraldehyde. Acetaldehyde boils at 21C so
it's less convenient to use, but unlike
paraldehyde it isn't a controlled drug.
Acetaldehyde is formed when paraldehyde
reacts with acidified water.

Staining solution.

Aldehyde fuchsine powder 0.25 g
70% ethanol              200 ml
Glacial acetic acid      2.0 ml

Leave overnight to dissolve. The
solution does not need to be filtered.

Method.

1. Stain hydrated paraffin sections, 5 minutes.
2. Rinse in running tap water (messy).
3. Immerse in 95% alcohol with 0.5% conc
hydrochloric acid until no more colour
is extracted (usually half a minute, but
not critical; acid alcohol doesn't
remove the real staining).
4. Counterstain if desired (e.g. haemalum
and fast green FCF).
5. Wash, dehydrate, clear and coverslip.

In some methods (eg for cystine-rich 
proteins including insulin and classical
neurosecretory material) an oxidizing step
is put in before staining: 0.5% potassium
permanganate in 2% sulphuric acid, 5 min,
followed by a rinse in 1% oxalic acid to
remove brown deposits of manganese dioxide
from the sections, then wash in water.
-- 
-------------------------------
John A. Kiernan
Department of Anatomy and Cell Biology
The University of Western Ontario
London,   Canada   N6A 5C1
   kiernan[AT]uwo.ca
   http://publish.uwo.ca/~jkiernan/
   http://instruct.uwo.ca/anatomy/530/index.htm
_______________________________
"Marshall Terry Dr, Consultant Histopathologist" wrote:
> 
> John tells us:
> "It is also possible to recover
> the aldehyde fuchsine as a precipitate that can
> be collected by filtering, dried and stored
> for 10 or more years."
> 
> OK John ......how?
> (This would solve my problem of needing it every 4 months only and suffering the groans of the techs at having to make it up again)
> 
> BTW - I am sure that someone suggested a paraldehyde substitute at one time, but I omitted to keep the post.
> 
> Dr Terry L Marshall, B.A.(Law), M.B.,Ch.B.,F.R.C.Path
>  Consultant Pathologist
>  Rotherham General Hospital
>  South Yorkshire
>  England
>         terry.marshall <@t> rothgen.nhs.uk
> 
> -----Original Message-----
> From: John A. Kiernan [mailto:jkiernan <@t> uwo.ca]
> Sent: 17 August 2005 16:11
> To: Histonet
> Subject: Re: [Histonet] aldehyde fuchsin
> 
> The solution of aldehyde fuchsine has a rather
> short shelf-life (8 weeks) so it's best to make
> up your own. It is also possible to recover
> the aldehyde fuchsine as a precipitate that can
> be collected by filtering, dried and stored
> for 10 or more years. Solutions made from aldehyde
> fuchsine powder (0.125% in 70% ethanol with
> 1% acetic acid) are more stable than the traditional
> directly made solution, being good for about 2 years.
> 
> It is said that solutions of aldehyde fuchsine
> made from the powder will not stain pancreatic
> islet B cells without prior permanganate oxidation
> (see Mowry,RW 1978 Stain Technol. 53: 141-154. This
> paper also has useful tips for other uses of
> aldehyde fuchsine.
> --
> -------------------------------
> John A. Kiernan
> Department of Anatomy and Cell Biology
> The University of Western Ontario
> London,   Canada   N6A 5C1
>    kiernan[AT]uwo.ca
>    http://publish.uwo.ca/~jkiernan/
>    http://instruct.uwo.ca/anatomy/530/index.htm
> _______________________________
> Robin Newlin wrote:
> >
> > Hi All
> > Does anyone know if aldehyde fuchsin is available commercially, or do I have to brew my own.
> > Thanks
> > Robbin Newlin
> > Manager, Cell Imaging/Histology Core Facility
> > The Burnham Institute
> > 10901 N. Torrey Pines Road
> > LaJolla, Ca. 92037
> > 858-646-3100 ext.3552
> > _______________________________________________
> > Histonet mailing list
> > Histonet <@t> lists.utsouthwestern.edu
> > http://lists.utsouthwestern.edu/mailman/listinfo/histonet
> 
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