[Histonet] Expiration Dates on Reagents
Owen, Michael P
michael.owen <@t> fda.hhs.gov
Thu Apr 19 08:21:30 CDT 2007
Dear List Members,
My laboratory had many reagents that were very old before it prepared
for ISO 17025 status in 2004. I found a bottle of Methylene Blue powder
dated from 1965 and a Loeffler's Alkaline Methylene Blue solution from
The facility has many individuals slow to change, therefore control of
expired reagents can be a challenge occasionally. The laboratory is
doing better than in the past. I will be interested to see what the A2LA
re-assessment for ISO 17025 accreditation maintenance occurring next
week will discover on this issue. :o)
Based on observations like the ones given above, my laboratory has
established the following guidelines for its work. Although it is a FDA
facility, the concepts of CAPA and quality controls in their own
laboratories is a new concept to many FDA scientists.
* DISCLAIMER* I would not consider these SOPS/guidelines as ones that
would be accepted in your own facilities if you are under FDA
jurisdiction. Note also my laboratory primarly tests foods and performs
limited histochemical work which is usually on pure cultures. :o)
Quality Assurance of Microbiological Media, Reagents, and Locally
Sterilized Equipment SOP
3. The following schedule will be followed for prepared media,
components and reagents for which specific directions on expiration date
are not provided:
a. Tubed or bottled media (<1 liter): screw capped, 180 days;
slip-capped, 90 days; some exceptions apply. Media in slip-capped tubes
used less regularly may be stored at refrigeration
temperature to avoid excessive evaporation.
b. Large bottled media, including agar (> or = 1 liter): 90 days.
c. Agar plates: 90 days (with some exceptions).
d. Sterile reagents in screw capped container, e.g. saline, distilled
oil, and glycerol: 1 year.
Chemical Mangaement SOP
The Industrial Hygeinist will assign a five-year expiration date to
stock chemcials started from the date of receipt. Five years will be the
expiration date unless otherwise specified.
For in-house prepared reagent solutions and/or solvent mixtures, an
expiration date (shelf life span) of one year will be assigned unless
another SOP or procedure dictates otherwise.
Michael P. Owen, Regulatory Microbiologist
U.S. FDA Pacific Regional Lab Northwest
22201 23rd Drive SE Bothell, WA 98021-4421
Phone: 425-483-4865 E-Mail: michael.owen <@t> fda.hhs.gov
More information about the Histonet