[Histonet] Grocott's Methenamine Silver Stain

[Kathleen Roberts]

I am not sure how long they were in decal...but I supplied some of our 
Fisher Scientific Cal-EX, which has hydrochloric acid and EDTA in it, to 
the Rutgers vet who had this case of sneezing rats.  I did ask him how 
long he decal'd them, but he doesn't remember either.

The chromic acid was freshly ordered as a 10% solution from LabChem, 
Inc., which was then diluted down to 4% the morning I was to use it.

Thanks for your help!
Kathleen

Bartlett, Jeanine wrote:

> Kathleen:
>
> How long were they in decal and what type of decal?  And do you make
> your chromic fresh?
>
> Jeanine Bartlett, HT(ASCP)
> Centers for Disease Control
> Infectious Disease Pathology Activity
> 1600 Clifton Road, MS/G-32
> Atlanta, GA 30333
>
>
> -----Original Message-----
> From: histonet-bounces <@t> lists.utsouthwestern.edu
> [mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Kathleen
> Roberts
> Sent: Wednesday, May 05, 2004 1:54 PM
> To: 'histonet <@t> lists.utsouthwestern.edu'
> Subject: [Histonet] Grocott's Methenamine Silver Stain
>
>
> Hey, all-
>
> I've been trying to stain some FFPE slides of decalcified rat sinuses
> for fungi using the AFIP protocol for Grocott's stain, and despite using
>
> fresh reagents, the positive control and unknowns do not stain at all,
> except for some random deposition of silver that does not even begin to
> look like fungi.  The positive control is loaded with Candida, and can
> be seen with H&E easily.
>
> So far, we don't see any fungi in the rat sinuses and lungs (they were
> sneezing, and the bedding came back positive for Aspergillus) with H&E
> staining, which is why we decided to try the Grocott's-one way or
> another we should be able to visualize it in the tissues.
>
> Any ideas why the Candida-loaded positive control would not stain with
> Grocott's?  Right now I am thinking that perhaps they didn't sit long
> enough in the 4% chromic acid, even though the protocol says to soak the
>
> slides for an hour to oxidize them. Either that or a longer soak in the
> methenamine-silver solution at 60 degrees C (also for one hour).
>
> Thanks in advance for your help-
> Kathleen Roberts
> Principal Lab Technician
> Neurotoxicology Labs
> Dept of Pharmacology & Toxicology
> Ernest Mario School of Pharmacy
> Rutgers University
> 41 B Gordon Rd
> Piscataway, NJ 08854
>
>
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