Re: Daily Digest

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From:"Andre J. Balaton" <>
To:"HistoNet Server" <>
Date:Sat, 22 May 1999 09:46:27 +0200
Content-Type:text/plain; charset="iso-8859-1"

ORIGINAL MESSAGE  dated: 18 May 1999 09:14:29 -0500
From: Dana Settembre <settembr@UMDNJ.EDU>
Subject: Re-using

Does anyone re-use citra buffer  and H2O2 for surgical specimens?
If the answer is yes, how long for each one?

Dana Settembre
Immunohistochemistry Lab
University Hospital
Newark, NJ


Dear Dana,

We perform heat-mediated antigen retrieval in a pressure cooker containing 2
L EDTA every day and
re-use EDTA for 4 weeks. On a few occasions, we may change the EDTA solution
if it looks filthy or contains tissue fragments or if our tissue positive
controls seem to stain a bit weaker than usual (e.g. ER/RP, MIB-1,CD 30).

Andre J. Balaton
Centre de Pathologie


ORIGINAL MESSAGE dated: 18 May 1999 09:28:31 -0500
From: Margaret Blount <>
Subject: Ag Retrieval

          I too would be grateful for any guidelines, we at present
          use a pressure cooker but owing to local safety regulations
          we have to throw out a perfectly good pressure cooker and
          replace it with a new one every year! Because it is cheaper
          than having it tested, in case you wanted to know. I imagine
          that this would not be the case with a veggie steamer as
          pressure is not involved. The other issue is this, are the
          results as consistent as with a pressure cooker?

          Margaret Blount
          Unilever Research


Dear Margaret,

We've been using domestic pressure cooker for many years for antigen
retrieval. Some high quality models are guaranteed for life ! And this
guarantee is valid as long as you change the rubber seal every year as
stated in the manufacturer's recommendation. So we change the rubber seal
every year and keep our pressure cooker.
The main problem is that in some safety officers will not accept a domestic
equipment to be used in a lab. If so, you will have to buy a so-called small
laboratory mobile autoclave : it looks exactly like a domestic pressure
cooker but may have a pressure indicator and costs 7 X or 10 X more money.

Andre J. Balaton
Centre de Pathologie

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