[Histonet] Re: Finding Lymph Nodes After Fixation

[Wiese, Jason VHAROS]

Presto-fixe II Active ingredients:

1.0 Molar Formaldehyde
0.2 Molar Glyoxal
60% Methanol

Buffered plus PVP(macromolecular colloidal membrane protectant)

That's it...

I agree with you 100% on the clinical seriousness of this problem.  I am
in no way saying that presto-fixe II will solve this problem, nor am I
endorsing the product as some great mystery which has been overlooked.
I only know that, at times, I have place mesentery that has been sitting
in formalin for a long time (days) in this product, and I have noticed
the nodes turn white and firm up a bit.

Thanks,
Jason



-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu
[mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of
rsrichmond <@t> aol.com
Sent: Tuesday, April 24, 2007 4:46 PM
To: histonet <@t> lists.utsouthwestern.edu
Subject: [Histonet] Re: Finding Lymph Nodes After Fixation

Well, three different people have claimed they can get away with 
post-fixing colonic mesenteries in a disclosing fixative to look for 
lymph nodes. I'm surprised - theoretically it shouldn't work, in my 
personal experience it doesn't work, and several people have told me 
that they couldn't make it work - so I felt justified in pontificating. 
Well, I'll try it again if the opportunity arises.

I wonder if the mesenteries received in formalin were adequately fixed 
- it's a situation where formalin penetrates very slowly.

My personal preference is Davidson's fixative (3 parts water, 3 parts 
alcohol, 2 parts 37% formaldehyde solution, 1 part glacial acetic 
acid). Surgipath's O-Fix in my experience works quite as well. I've had 
no luck Googling "Presto-Fixe II from spectra-tint" - look at the MSDS 
and tell us what's in it.

Once again I want to emphasize the clinical seriousness of this problem 
- lymph node metastases from colon cancer are often the size of 
pinheads, very hard to find - and their presence determines treatment.

Bob Richmond
Samurai Pathologist
Knoxville TN
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