OK, since our dear Samurai Pathologist dragged me into this, here's 
my 2 cents' worth (thanks for the plug, Bob!).

The basis of any procedure for Barrett's esophagus is to 
differentiate neutral (gastric-type) from acidic (intestinal-type) 
mucus.  As John Kiernan pointed out, AB + PAS is the standard method. 
The typical sequence using Alcian blue first is possible today, at 
least with Anatech's certified dye powder or stain solution.  Color 
differentiation is fine (for a color photomicrograph, see our 
website:  select Product Literature, then Innovators, then "Searching 
for Helicobacter".  The last page contains the picture;it is not 
Barrett's esophagus, but it shows neutral vs. acidic mucus).

Actually, my favorite was Maxwell's procedure until Alcian yellow 
disappeared.  For a look at that, see our Innovator titled "Three 
Dyes, Three Dilemmas".  Maxwell stained first with AB (the example in 
the Innovator used pH 1.0, but for Barrett's I would use 2.5-2.8). 
This is followed with periodic acid then sodium metabisulfite then 
Alcian yellow.  We finished it off with a red nulear counterstain, 
Brazilliant!.  The color contrat between emerald green acidic mucus 
and bright yellow neutral mucus is spectacular.

You can obtain the same results without Alcian yellow by using our AB 
at 2.5-2.8; followed by 1% periodic acid for 10 min, then our Hp 
Yellow stain.  Hp Yellow is a yellow Schiff-like reagent (technically 
pseudo-Schiff, but don't worry about that here).  AB stains only the 
acidic mucus.  Periodic acid oxidizes nearly all mucus to their 
aldehyde forms, which then react very specifically with Hp Yellow (or 
regular Schiff's Reagent).  Follow the Hp Yellow with a 10% aqueous 
acetic acid rinse to remove ionically bound yellow dye.  Counterstain 
nuclei red for best contrast.  Brazilliant! provides a Harris-type 
crispness to the chromatin, which really enhances the picture. 
Complete directions are included in the package insert for Hp Yellow. 
Naturally the specimen must be properly fixed and processed for best 
results.

If anyone has a control block of Barrett's esophagus I would love to have it.

Dick

-- 
Richard W. Dapson, Ph.D.
Anatech Ltd.
Battle Creek, MI
800-ANATECH (800-262-8324)
269-964-6450
email@anatechltdusa.com
Web address:  anatechltdusa.com