Expiry dates for general molecular biology reagents - (Aug/30/2007 )

We've just had an ISO9001 audit and one of the things that this brought up was that to work to GLP we need to have expiry dates on all our reagents and chemicals.

This was rasied at a recent lab meeting and led to a shouting match. One person now has 2015 in very big bold letters written on all her bottles. Another person was told exactly were she could stick her plan to throw out all bottles without sensible dates and people were generally confused and wanted advice

It has fallen to me to come up with a sensible plan to which everyone can agree (yeah right!).

I've kinda settled on a one year review date at which point reagents are reassessed and if we have any reason to suspect problems they are binned but if not then extend the expiry date for another year.

This could also cover all those resistiction enzymes we have that are five years out of date but still work fine (and that the auditor didn't see)

I'm also coming up with a list of things that need shorter dates and can / can't be extended.

So I was wondering what other labs do? What is a reasonable expiry date for things like TE, TBE, LB etc etc ? A google search didn't really come up with anything. Anybody got any ideas, resources, ways to stop me getting linched at the next lab meeting as it has now become "my problem"

thanks

Ian

I would suggest reading a book on chemistry and getting acquainted with some basic understanding of chemistry.

I belong to a DNA lab and nothing with a short shelf life is kept in any quantity. Things which have a short shelf life.. well that to my knowledge is T4 ligase and CIP... about every thing else can last for years if not decades.

This situation really does sound like an evil conspiracy for an evil company that want you to throw away all your chemicals so that they can sell you new stuff.


TE, TBE, the solutions will last for decades. Kept sterile and uncontaminated, there is no reason to discard them. Of course a former labmate's half used TE, is not a candidiate for keeping. One can not rule out contamination.

LB... powder will last several years. Kept in an a dry and air tigh container.. probably a decade. Once made in to solution or agar, I would say it is probably good for a year. One should not make up so much wet media that you need to consider this situations.

All inorganic salts will last indefinately. (We are looking at geological time)
Simple organic salts will also last the same.

Organic powders will probably last years if kept dry and in air tight containers (which they should be)
Unstable orgnic powders (like dry antibiotics) should be kept in freezers (-20 or -80) Stored in such conditions they too will last for years.

I have restriction enzymes in my lab's freezer that were purchased in 1988. The enzyme still cuts fine.

We have the same problem.
As a rule, all the solution must have an expiration date and we can't use if it's expired no mater we know solutions are ok.

What I do is trying looking for recommendations in “Molecular cloning” or in suppliers webs and I try to use the same criteria.

For ISO, You know, ISO don’t tell you what to do. It just tells you have to have all your process well described and documented. So I think for restriction enzymes and stuff like that, you could have a procedure saying something like: after 5 years, every enzyme will be tested every year digesting lambda with it (you’ll describe the procedure to test them).

We had the same problem.

As a rule, all the solution must have an expiration date and we can't use if it's expired no mater we know solutions are ok.

What I do is trying looking for recommendations in “Molecular cloning” or in suppliers webs and I try to use the same criteria.

For ISO, You know, ISO don’t tell you what to do. It just tells you have to have all your process well described and documented. So I think for restriction enzymes and stuff like that, you could have a procedure saying something like: after 5 years, every enzyme will be tested every year digesting lambda with it (you’ll describe the procedure to test them).

In that document you’ll explain enzymes could be active for year and give a reference.

well it's a general rule that all solutions of a forwer member are discared (except expensives ones...)
we prefer to note the date which the solution was made, and write initials (for recognizing the bottle as well as trust in a solution : our techician is very talented, so when you ask may i take part of your solution we're pretty sure it won't break the experience)
expiration dates usually i take in count is
sterility : i think 1year is the limit
pH : i would check it after a long period of non use
touch chemicals : datas on stability in solution are given generally on technical bulletin, and you may ask the brand manuacture to informations for that.

LB : liquid it's till contamination, but as we do several cultures, the turnover is pretty short
LB agar + ab : 6month
cell culture medium : 6month at most, but like i wrote for LB, bottles are of 500ml, and are quickly finished to care about expiration date. oreover, for antibiotics there is expiration date written. Once, the date was passed. So i just re-did a killing curve and amount needed hasn't changed.

I use recently a detection medium of a kit. Supposed to be dead after 4weeks, i was frightened because i really needed it and can't get my boss to purchase little extra. Well, the medium was prepared 1year and a half ago, and worked well in the control experiments.

We have had the same problems and did the same thing as you suggested. On every bottle of reagent that we make and know doesn't go bad, is unstable or is used a lot (short turnover means we don't put expiration date on there, bottles of media usually are replaced within a week!) we put exp date one year from when it's made. One year down the road we check it, see if we can still use it. If we don't trust it we throw it out.
This is already a very big step since before I came here people would still use reagents that have been made by former labmembers without even checking the pH.

Thanks for all the advice, we have a quality department (9 of them, not sure what they do?) who have produced loads of documents which include one mandating "expiry dates on bottles" (Guess I've answered my question, they write documents)

I guess the way to go is to have one year " expiry review dates" on most things and have the option to extend the date after a review of the reagent. This review could include postitve control experiments and a simple is it couldy / ppt / changed colour?
I am also planning a list of known unstable reagents which have to have shorter expiry dates.
Oh and of course a whole tree of paper work to document all this.


I found this cartoon which was quite good


Dilbert on ISO9000

Luckily, our lab is not ISO.

Therefore, we can use chemicals that is over 10 years old.

Just wondering.
What is the purpose of ISO??