John,
        haven't seen a published report on this but think that this depends
to a
large extent on the source, type of antibody and the method of preparation
of the
antibodies. Supernatants from monoclonal antibody ( tissue culture ) in our lab
were generally kept at refrigerator temperature and had a useful life of 3-4
years. They did not do so well if they were frozen, however, this was not a big
problem as we also retained the frozen cell clones.
Commercially prepared samples if frozen in small aliquots and kept at -80C
generally appeared to last for several years. The secret was  to avoid repeated
freezing and thawing the entire stock, as it was suggested that each time
thawing
was carried out a 5-10% loss of reactivity occurred.
If the antibodies are coupled to markers then this its a different story. Some
cannot be frozen and thawed as they tend to break down. Seems to me that
this is
especially true of  some peroxide coupled antibodies. Some coupled antibodies
can be purchased as freeze dried samples and stored (I suspect more or less
indefinitely) in the freezer.
All samples of antibodies do however need to be kept in well sealed vials, no
matter how they are stored.
Barry.


"J. A. Kiernan" wrote:

>   You'd think the immunologists would have sorted out optimal
>   storage conditions years ago. I have talked to a few local
>   ones, and they  work by "common sense" and hearsay:
>   avoid repeated freezing/thawing; use -80; -20 is OK;
>   +4 and throw out in 6 months; etc. No consistency at all.
>   A general suspicion exists of suppliers' expiration dates,
>   which might be contrived to make us buy more often.
>
>   Has anyone seen a published comparative study, in a
>   regular peer-reviewed journal, of the effects of
>   different storage conditions on different kinds
>   of antibodies?
>                    John Kiernan, London, Canada.
>
> On Mon, 22 Feb 1999 rschoonh@sph.unc.edu wrote:
>
> > I have been using antibodies that were made for us ~12 years ago which were
> > aliquated and stored in one of our -80 freezes and they still work
> > perfectly.  Don't know about storing them at -196, I would doubt that it
> > would hurt them but I don't think that it would extend their usfullness.
> >
> > I do know that when these same antibodies were stored at -20 (some were put
> > in the -20 by a predecessor) they started to lose potency after about 3
> > years.  That was when I 'discovered' the ones stored in the -80.

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