Tom Phillips wrote:
>
> The other big problem with -20 freezers is that they so often are
> "frost-free" these days.  The auto defrost cycles on these types of
> freezers are very tough on antibodies and sensitive enzymes.  I
> believe Jackson recommends diluting their antibodies in 50% glycerol
> if you want to store at -20 so that they don't "freeze" but yet are
> kept cold.  I don't know if that limits the damage by a frost-free
> freezer but do know that the molecular biology types all stress that
> their enzymes diluted in glycerol are still very labile if stored in
> a frost-free freezer.

We typically store ours at -20 in glycerol and have no problems.  It's a
good compromise, since you can pipette out just what you need.

Martin
--
Martin Wessendorf, Ph.D.                        office: (612) 626 0145
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