[Histonet] PAS Stain

[koellingr at comcast.net]

An excellent point.  For anyone wanting to investigate-simply do a PubMed search on variation of AMY1 gene.  Sorry; I guess I should say this is, strictly speaking, non-histology related topic and I don't want to get into trouble as some before me.  Tons of research about this linking back (in theory) to positive selection in hunter-gatherers versus agricultural ancestors, race, obesity, phenotypic and dietary differences as to why maybe there can be big differences. 
Spokane Ray 

----- Original Message -----

From: "Bob Richmond" <rsrichmond at gmail.com> 
To: koellingr at comcast.net 
Cc: "Histonet at lists.utsouthwestern.edu" <histonet at lists.utsouthwestern.edu> 
Sent: Thursday, May 5, 2016 11:35:42 AM 
Subject: Re: [Histonet] PAS Stain 

Spokane Ray points out something I've wondered about for years - can just anybody spit on the slide and remove the glycogen? I've never heard of any variation, but the number of people I've asked is very limited. This reference: 
http://www.ncbi.nlm.nih.gov/gene/276 
certainly suggests that different people have different salivary alpha amylase activity. 

Bob Richmond 

On Thu, May 5, 2016 at 2:27 PM, < koellingr at comcast.net > wrote: 



I love having the Samuri Pathologist on this forum for wisdom and real-laboratory life knowledge.  And yes, I have in the past spit on slide ON OCCASSION when faced with a dire necessity.  Although I know there are those who would wretch about this; it remains a fact of viable laboratory life for some. 
  
My problem now is that in this era of (MUCH TOO MUCH) regulation, how do you "test lots" or control from "lot-to-lot variation" in this SOP?  When Jane or Joe do this routinely and then goes on vacation, what about Sally or Jim spit?  There is a variation in copy number of the AMY1 gene (amylase) and resulting difference in amylase protein concentration amongst individuals. 
  
Why not just standardize it from the start, reagent, pH, temperature and it really cannot fail. 
  
Spokane Ray 


From: "Bob Richmond via Histonet" < histonet at lists.utsouthwestern.edu > 
To: " Histonet at lists.utsouthwestern.edu " < histonet at lists.utsouthwestern.edu > 
Sent: Thursday, May 5, 2016 11:10:40 AM 
Subject: Re: [Histonet] PAS Stain 


Amylase (diastase) for the PAS stain queries: 

Whatever happened to spitting on the slide (30 min at room temperature)? 
John Kiernan advises "thinking of lemons and drooling into a small beaker" 
though I'd advise chewing on a rubber band for a few seconds. 

He notes that alpha amylase is preferred. I'd go with the cheapest one in 
the Sigma-Aldrich catalog. Room temperature is usual, but I note that Sigma 
offers a heat-stable alpha amylase. 

Bob Richmond 
Samurai Pathologist 
Maryville TN 
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