[Histonet] Alcian Blue deposit

[John Kiernan]

If an alcian blue solution contains insoluble 
material, or if insoluble material forms after 
filtering, the solution must be no good. Solutions 
at pH 1.0 or pH 2.5 can be stable for some years. 
Solutions of alcian blue used in "critical 
electrolyte concentration" procedures are stable 
for only a few hours. See Horobin 2002 - Ch.26 in 
Conn's Biological Stains, 10th edn.

Insoluble blue material is almost certainly copper 
phthalocyanine pigment. The books say this 
dissolves in concentrated sulphuric acid, but it 
can't be removed with any ordinary solvent.

Alcian blue has been available as a certified dye 
powder since 1981, so use only a certified batch. 
The solid dye powder can sometimes deteriorate; 
this may be related to dye purity, with certain 
non-dye additives (notably boric acid) improving 
stability. Generally, solid dyes are stable for 
many years.

A related dye is the alcian blue pyridine variant 
(Sigma-Aldrich), which is more stable and reliable 
than alcian blue (see Churukian, Frank & Horobin, 
2000 Biotech. Histochem. 75: 147-150; Henwood 2002 
Biotech. Histochem. 77: 93-94.) With the pyridine 
variant you do not obtain a completely 
acid-resistant product like that produced by 
staining with real alcian blue, but that may not 
matter for many purposes. Another more stable 
alcian blue substitute is alcec blue; I don't know 
if this is still available. The most recent alcec 
blue publication (of very few) that I've seen is a 
nicely illustrated 2001 paper on sulfoglycolipid 
storage disease by Lullmann-Rauch et al, in 
Histochemistry & Cell Biology 116:161-169.
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John A. Kiernan
Department of Anatomy and Cell Biology
The University of Western Ontario
London,   Canada   N6A 5C1
    kiernan[AT]uwo.ca
    http://publish.uwo.ca/~jkiernan/
    http://instruct.uwo.ca/anatomy/530/index.htm
_______________________________
SARAH REEVES wrote:
> Hi
> 
> Does anyone have any ideas to reduce alcian blue deposit on sections.  We filter the solution after making up as well as immediatly before use.  
> 
> Thanks
> Sarah
> www.kentandmedway.nhs.uk
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