[Histonet] Counter stain for PAS for fungus (Steve McClain)

[Rena Fail]

earlier I  recommended using light green yellowish  as a counterstain for
Pas for fungus. Some Pathlogists  prefer the green counterstain when
staining with PAS for fungus. Using a 5% chromic acid solution as the
 oxidizer and controlling the time and temperature" will eliminate reactive
aldehydes in all but the structures that have the greatest concentration of
carbohydrate " Using chromic acid makes it much easier to detect fungus
 Histologic Dec.2005 XXXVIII(2):35
Rena Fail

the first pathologist I worked for had AB-Pas stains done every day and you
are right they are wickedly good.

On Thu, Jul 26, 2012 at 4:31 PM, Steve McClain <SteveM <@t> mcclainlab.com>wrote:

> Change all your reagents.
> Change periodic acid every week at least.
> PAS unlike many other stains is a chemical reaction and is sensitive to
> oxidizer
>
> Personally I see little advantage in fast green, and a common downside is
> overstaining in many labs, hiding fungus and basement membrane.
> Faint Hematoxylin is acceptable counterstain.
>
> For certain applications, e.g., dual staining for carbohydrate and mucin,
> by adding AlcianBlue for 40 seconds is wickedly good.
> Dis/Advantage being dual staining methods impose two charges.
> Too bad.
> Instead of separate stains for mucin and carbohydrate,
> do them both every day and get good at it.
> We rarely do a straight PAS any more, either PAS+AB+H or PAS+AB
> Subtract the second charge where needed.
>
> The two analytes (carbohydrate and mucin) are different, yet the
> interpretation is synergistic.
> Where you see mucin glommed around a hypha-like structure it is.
> AB also demonstrates conidia and microconidia and internal structure in
> many fungi.
>
> AlcianBlue also stains bacteria, making it useful where polymicrobial
> (fungal and bacterial) infections are common.
> Consider it your biofilm assay.
>
> Many fungi produce mucin making PAS-AB with hema a superb method for
> detection.
> PAS-AB sine hema is considerably more sensitive, especially with pigmented
> fungal species,
> but interpretation of PAS-AB without Hema is more difficult for
> pathologists.
>
> Steedman wrote the original description , in 1951 and it remains the best
> paper.
>
> Steve
> Steve A. McClain, MD
> McClain Labs, LLC 45 Manor Road, Smithtown, NY 11787 631 361 4000
>
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