[Histonet] Metabisulfite rinse for PAS reaction (potassium vs sodium)

[Monson, Frederick]

And,  I always rinsed the Schiff with 'absolute' HOH before the tap water rinse - which rinses were taken from my protocol for Ehrlich's 'Acid' Hematoxylin that was mixed from scratch and aged in the second story deep window sills on the West wall of the Biology/Geology building at Lehigh University - usually left, after mixing, with a cotton plug, for around 6 months [with periodic compensatory 'absolute' water additions to the bottle].

A.	Ageless NOTE:  One of the most important phrases in organic chemistry is 'tautomeric shift.'  Especially for biologists - most of whom never heard the phrase.  Follow-up after GOOGLE:  Why is tritium so dangerous...?

B.	Current NOTE:  98% of science folk - after decades of programming - don't know how many digital cameras they carry with them every day.

C.	HISTO_EXPERIMENT:  next time sections are taking fresh, UN-fixed tissues, in the cryostat, and when time permits, do the following.
		1.  set 5 or more sections on glass slides - or coverslips - and set them aside IN the cryostat
		2.  immediately remove one and after thawing - very little time - and NOT treating with PA, immerse the specimen directly in Schiff's solution for the standard time and follow with the usual rinses and counter dye(s)-BUT, I left them out!
		3.  at one hour intervals repeat (2) with one of the remaining sections.
		4.  when you want a counter dye, please help yourself.
		5.  if the outcome resembles mine in 1968, explain what you have observed.

Cheers to all,

Fred Monson
On the 16th of June, 16 days from my 78th, I will retire to do other things.  That, at least, is the plan!!

Frederick  C. Monson, PhD
Technical Director
Center for Microanalysis and Imaging, Research and Training (CMIRT)
West Chester University of PA
Geology-Astronomy
750 South Church St.
West Chester, PA, 19383
fmonson at wcupa.edu
610-738-0437(Work)



-----Original Message-----
From: Bryan Llewellyn via Histonet [mailto:histonet at lists.utsouthwestern.edu] 
Sent: Monday, March 06, 2017 9:28 PM
To: Histonet <histonet at lists.utsouthwestern.edu>
Subject: Re: [Histonet] Metabisulfite rinse for PAS reaction (potassium vs sodium)

You can use either the sodium or potassium salt. Both can also be used to make Schiff's reagent as well. In fact, many histotechs leave out the sulphite rinse step and simply rinse off in water and wash well with tap water. It seems to work just as well.

Bryan Llewellyn


Angela Lamberth via Histonet wrote:
> In Carson’s 3rd edition, the reducing rinse following Schiff for PAS 
> is 0.55% potassium metabisulfite (pg 137-138). For PAS/AB the reducing 
> rinse is given as sodium metabisulfite (Carson pg 149).
>
>
>
> My other texts (Sheehan/Hrapchak as well as Vacca) list the reducing 
> rinse as sodium metabisulfite which makes sense to me since the Schiff 
> is made with sodium metabisulfite.
>
>
>
> Is this a printing error in the Carson book? I appreciate any light 
> anybody can shed on this.
>


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