I agree with John, I have used saturated tartrazine in 70% cellosolve as a
counterstain to PAS for over 35 years. The solution is much more stable than
Metanil yellow. Martius yellow is an excellent alternative, as is an
alcoholic solution of Picric acid. I know, I know!!! All you safety minded
people stay OFF my back!

Bryan

> ----------
> From: 	J. A. Kiernan[SMTP:jkiernan@julian.uwo.ca]
> Sent: 	October 7, 1999 12:33 AM
> To: 	Histonet
> Subject: 	Re: Thomas Histology (metanil yellow)
> 
> On Thu, 7 Oct 1999, Ken Turner wrote:
> 
> > I have a copy of Thompson, which, on page 480 gives a metanil yellow
> > counterstain after PAS. The solution is: 0.25% metanil yellow in 0.25%
> > acetic acid prepared with distilled water. Mix, filter and store in a
> clean
> > brown bottle.
> > After conventional periodic acid and Schiff sequence, and water washing,
> > stain 1 minute in metanil yellow, rinse in distilled water, 95% ethyl
> > alcohol, absolute ethyl alcohol and xylene. Thompson suggests mounting
> with
> > Permount.
> 
>    For what it's worth, I agree 100%.  Metanil yellow provides
>    a splendid yellow counterstain for cytoplasm and collagen.
>    Unfortunately the dye solution is not very stable. Its colour
>    changes to brown over the course of a few months, and the
>    staining properties also deteriorate. I don't know why, but
>    it's so. For another yellow anionic dye you might try
>    tertrazine. Look it up in Bryan Llewellyn's StainsFile: a
>    splendid collection of histo-wisdom.
> 
>  John A. Kiernan,
>  Department of Anatomy & Cell Biology,
>  The University of Western Ontario,
>  LONDON,  Canada  N6A 5C1
> 
> 
> 
>