Most dye powders do not go bad with time/age, and some (Giemsa for
example) seem to get better.

The best thing to do is to first, write a policy that states dyes can
continue to be used if they are checked via staining periodically 
(every year, every other year, whatever you decide), and that their
quality is determined to be adequate.

Then, make up a staining solution like you would for the stain - 
and stain using the appropriate control that you usually use for 
that stain. Document whether it did or did not work. 

If it did work, save the slide as evidence, record your success, 
state when the next expiration interval is (1, 2 years, whatever) 
and continue using the dye until that next expiration date. Repeat. 

If it didn't work, throw it out. 

If it worked somewhat (like - OK, but weak), and if you feel like
playing around with it, then retest with slight modifications (like
add more dye, or change pH). Then retest. If OK, then record the
modifications, and make certain all future staining solutions
are made with this modification.

We have this policy, and so far, it has passes CAP inspections.

**************************

Peggy A. Wenk, HTL(ASCP)
William Beaumont Hospital
Royal Oak, MI 48073


"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.