[Histonet] Masson's trichrome

[John Kiernan]

Dear Julien Lambrey de Souza,

I have done a Masson variant closely similar to the one
you refer to, and am an admirer (and lucky owner) of 
Gabe's big 1976 book. I suspect that the cause of your
trouble is the fixation. Were your specimens fixed in
a solution that had formaldehyde as the only chemically
active ingredient?

Gabe (like Mallory, Heidenhain and Masson) fixed specimens 
in mixtures appropriate to trichrome staining methods. 
Such mixtures contain acetic acid and either picric acid, 
mercuric chloride or potassium dichromate. Examples are 
Bouin, Heidenhain's SUSA and Zenker. Sections of 
formaldehyde-fixed tissue do not give the crisp colour
distinctions that make trichrome preparations so 
beautiful and informative. 

In clinical laboratories, where specimens are almost
always fixed in neutral (usually phosphate-buffered)
formaldehyde, the hydrated sections can be exposed to a
trichrome-friendly fixative compound before doing a
method like Masson's. This trick usually allows the
dyes to distribute themselves correctly into cytoplasm 
and collagen. 

The customary pre-treatment is immersion of 
rehydrated slides in Bouin's fixative either 
overnight at room temperature or for an hour or two 
in an oven at about 60C. My (unpublished and
probably not original) observations indicate that 
saturated aqueous picric acid is just as 
effective as Bouin (thus avoiding fumes of 
formaldehyde and acetic acid). 

If your specimens were not fixed in formaldehyde,
provide more information and keep on asking. There
are (I thinnk) a few thousands of Histonetters.
Someone else may have encountered and solved your
problem.

John Kiernan
Anatomy, UWO,
London, Canada
__________________________________________
Julien LambreyDeSouza wrote:
> 
> Hello,
> 
> I am trying out Masson's trichrome for the first time. I used the Goldner
> modification from Gabe 1976, with Fuschine-Ponceau, orang-G phosphomolybdic
> and Light green. We are staining 7 micron sections of entire fish larvae
> heads. When following the protocol (5 minutes in each color followed by a
> 1% acetic water rinse) I get a general green staining of all tissues. The
> only way to differentiate cartilage from the rest in our section is by
> recognizing cellular topography, same as with Hematox-eosine staining,
> therefore loosing the whole point in using Masson's trichrome. I seem to be
> doing something wrong.
> 
> Would anybody familiar with the technique be inclined to share their
> expertise or protocol? I would be happy to send a pic of our staining
> result by email to have input on the possible problem.
> 
> Thanks,
> 
> Julien.
> Julien Lambrey de Souza
> Assistant de recherche, Biologiste M.Sc.
> Biologie Évolutive.
> Université du Québec à Rimouski
> Département de Biologie, Chimie et Sciences santé
> 300, allée des Ursulines
> Rimouski (Québec) Canada G5L 3A1
> Tél.: (418) 723-1986 ext. 1714
> Fax.: (418) 724-1849
> Courriel: julien_lambreydesouza <@t> uqar.qc.ca
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