Forwarded: Re: reagents

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From:"Karen D. Larison" <>
Date:Tue, 10 Aug 1999 10:29:07 -0800


I have a 1998 note from the honorable Russ T Allison on this topic.  I copied it 
and taped it to my "dye" cupboard."  I hope it is useful to you as well.

Karen in Oregon

Date:          Tue, 07 Apr 1998 09:21:57 +0000 (GMT)
From:          RUSS T ALLISON <>
Subject:       Re: Shelf Life Studies

I have a copy of a study done by the Biological Stain Commission 
whereby 57 dry stain powders were tested for dye content and staining 
performance after a five year storage interval.
I will quote:
"The samples teasted were taken from the Commission's reference 
collection, which includes a sample of each lot submitted for 
certification since the inception of this program in 1922.  The 
samples chosen had been submitted for testing during 1968 and 1969 
(or earlier for a few dyes, no samples of which were submitted during 
these years) and were retested during the winter of 1973/74. 
(i.e.5yrs storage).  The samples were stored in brown glass bottles 
closed with plastic screw caps.....and had remained unopened 
room temperature. (20-25oC).
Changes in dye content were were in most instances quite negligible.  
In the five instances in which it showed a decline of more than 7%, 
the weight loss on drying a sample indicated that much of the decline 
could have been due to increase in moisture content during storage.
In no instance was there a perceptible change in the staining 
performance of any of the dyes at the time of retesting.
These results affirm and support the widely held view that under 
ordinary conditions of laboratory storage, biological stains in dry 
powder form have a useful shelf-life of many years.
Signed Victor M Emmel, Secretary, Elmer E Stotz, Treasurer.
The dyes with greater than 7% nominal loss of dye content were:
Aniline blue                       -11.2%
Fast Green FCF                -  7.3%
Acid Fuchsin                    -13.1%
Malachite Green                - 8.3%
Resazurin Tablets              - 8.9%  (What is that?)
Safranin O                        -11.8%
(I know that makes six!)
The report is dated July 26, 1974.
Does that help with your shelf-life decisions?
Russ Allison, Wales
Date:          Mon, 9 Aug 1999 16:23:12 -0400 (Eastern Daylight Time)
From:          Bert Dotson <>
Subject:       Re: reagents
To:            "William E. James Jr. H.T. A.S.C.P." <>
Cc:            HistoNet <>

In general 8 years is not very long on the shelf for many of the dyes 
you mention as long as they stay dry. I have been known to comb the 
dustiest of shelves in search of Congo Red lots from the fifties (they 
have a higer due content than anything you can buy now). Hematoxylin 
will also last for just about ever. As for testing, chemical and 
empirical tests for most common dyes are in "Conn's Biological 
Stains'" If you run across a jar of picric acid that has been around 
a long time, don't touch it, stop rummaging completely. Get some 
professional hazardous waste folks to help you out.

Bert Dotson

On Sun, 08 Aug 1999 19:22:53 -0600 "William E. James Jr. H.T. A.S.C.P." 
<> wrote:

> Hello,
>         I am looking for any info on the shelf life of reagents in dry
> form.
> ie: Eosin y, Hematoxylin, Congo Red, etc.
>         Will they last for more than 10-15 years and is there any way to
> test
> them for use.
>         I just started in the lab here at AML in Louisiana and the
> reagents
> here date back to 85 and in most cases none are less than 8 yeas old.
>                                                         thanx
>                                                 W.E.James Jr. H.T.

Bert Dotson

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