Hi Salvacion,

There are two articles I wrote concerning expiration dating in the EM Science
website under Tech Corner/ FAQ/Expiration dating.  I think you will find them
helpful for the chemical part of your question.  http://www.emscience.com

As far as dyes are concerned, I'm sure some will say they get better with age
and they really do.  I've used some dyes that I know had to be 15 years old and
they worked fine.  I would not say that for all though.  Dyes like giemsa or
wright stain will start to oxidize over time.

Rande Kline, HT (ASCP)
EM Science




"DeLovino, Salvacion S."  on 03/20/2002 02:34:09 PM

To:   Histonet@pathology.swmed.edu
cc:    (bcc: Rande Kline/EMI/Merck)
Subject:  Expiration Date




     Hello Histonetters:

     What's the usual shelf life of most chemicals and dyes when the
expiration dates are not indicated on the container? We have a whole lot of
old chemicals and dyes that we don't know if they're still good or not. Some
date back to the 60's! Thanks in advance.

     Salvacion S. Delovino