RE: Old Parformaldehyde

Nicholson, Janet (jkn1@CIDDAS1.EM.CDC.GOV)
Fri, 03 Nov 95 15:49:00 EST

The problem we have had with old paraformaldehyde is that with time, we get
increases in fluorescence (both autofluorescence and positive fluorescence),
which are most apparent when the samples are stored for more than a couple
of hours. It can be picked up after overnight storage in the refrigerator
of the sample in fixative. We make a working dilution once a week from 10%
stock.

Jan N.
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From: owner-cyto-sendout
To: Cytometry Mailing List
Subject: Old Parformaldehyde
Date: Thursday, November 02, 1995 6:48AM

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From: "Michael J. Herron" <herro001@maroon.tc.umn.edu>
Reply-To: "Michael J. Herron" <herro001@maroon.tc.umn.edu>
To: Cytometry Mailing List <cytometry@flowcyt.cyto.purdue.edu>
Subject: Old Parformaldehyde
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Date: Thu, 2 Nov 95 06:48:56 -0600
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I have read the warnings to only use "fresh" parformaldehyde for fixation,
but I
don't recall ever hearing why.

Could someone explain the sorts of artifacts that old paraformaldehyde will
introduce? And what exactly IS old?

______________________________________________
/ Mike Herron, U of MN, Dept. of Dermatology /
/ herro001@maroon.tc.umn.edu /
/ 612-625-8935 Box 124 UMHC, Mpls MN 55455 /
______________________________________________


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