I would try increasing your staining time.  I stain for 2 hours and 
have yet to experience over-staining.  

FYI - I keep my Alcian Blue stored at 4C when not in use, but bring it
up to room temp beforehand.  Also, I check the pH every time and adjust
as necessary.  I keep it for about 4 to 6 months and have no problems
with it fading unless it has been used excessively (we only need it on
an occasional basis).  My recipe is a 0.5% Alcian Blue solution in a 3%
acetic acid solution, pH 2.5, filter before using.  I like to pre-rinse
my slides in a 3% acetic acid solution to keep down the amount of H20
carry-over. Hope this helps!

-Katie 

--- Deborah Faichney <d.a.faichney@stir.ac.uk> wrote:
> This question comes via a student who is having difficulties in
> staining
> Rainbow Trout peritoneum.  Alcian Blue (8GX)pH2.5 prepared and used
> last
> week worked fine. When repeated today with identical tissue it would
> not
> stain.  Eventually after 1hr a faint blue could be seen but nothing
> like the
> previous section.  Any ideas?  
> He is trying to identify mucosubstances, any other tried and tested
> techniques that he could use?  We have been trying Alcian blue-PAS
> with some
> success, but again that was last week and we don't want to continue
> staining
> precious material if it is not going to work.
> 
> Thanks in advance for your help
> 
> Debbie faichney
> 
> Institute of Aquaculture
> University of Stirling
> Scotland
> 
> Debbie Faichney
> Institute of Aquaculture
> 
> 


===
Catherine "Katie" Bresee Bennett
Laboratory for Experimental Pathology
Department of Veterinary Pathology
Michigan State University

e-mail: bresee98@yahoo.com
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