Rita,

The general rule in trichrome staining is that a smaller dye molecule will
penetrate and stain a tissue element, but whenever a larger dye molecule can
penetrate the same element, the smaller molecule will be replaced by it.

If you are not using phosphomolybdic acid (a colorless acid dye of a larger
molecular weight), then you can rule out the selectivity of the aniline blue
(MW 800) or light green (MW 793) and it's action on the striated cardiac
muscle.

Acetic acid doesn't chemically alter any of the dyes, but only lightens
them.

To attain a more intense and consistent red staining of the muscle - slides
must remain in the heated Bouin's 56-60 degree C for at least 1 hour. Then
thorough washing under tap, to remove all traces of picric acid (MW 229)from
tissue, to allow the acid fuchsin (MW 586) to stain the cardiac muscle
without allowing the aniline blue or light green to penetrate.

Eric Kellar
Histology/Immunohistochemistry
University of Pittsburgh Medical Center


	----------
	From:  Rita [SMTP:angelrj@email.uc.edu]
	Sent:  Friday, February 26, 1999 12:09 PM
	To:  histonet@pathology.swmed.edu
	Subject:  Trichromes

	Dear histonetters,

		Our lab has been having a problem lately with our Masson's
Trichrome.
	We are usually staining mouse hearts.  Our muscle has been staining
	purple instead of red.  We have tried different times of
differentiating
	in acetic acid & length of time in Bouin's.  All our solutions are
made
	fresh or used within 3 months time.  This has also happened with our
	Gomori's Trichrome and we were purchasing the Gomori's stain
pre-made.
	It seems to work correctly at times, but it is very inconsistent.
Any
	suggestions would be appreciated.  Thank You.

	Rita Angel