I would like to thanks to everyone that took a few minutes to answer to
my question. The original query is bellow:
I would like to know which seal is best to seal deep wells with
crystallization screens for long term storage (up to six months).
Are thermo seals better than cold seals? I would appreciate if people
could tell me which seal they use, and at which temperature.
Thank you all in advance,
Those are the answers that I received:
We did extensive testing for this using caps, mat caps, tape, adhesive foil,
heat seal plastic, heat seal foil and the best way by far is heat seal foil.
It looks like the only loss we had was through the plastic of the plate not
through the foil while we had significant loss with the other methods. We
use Easy Peel heat seal from Abgene.
James M. Vergis, Ph.D.
we use the silicon mats that fit our deep wells and store the deep wells
usually we prepare 4 or 5 deep wells at a go. when needed, we thaw one
deep well and transfer the complete content to some 15 96well
crystallization plates. these, again, we freeze at -20 (sealed with
crystal clear film) and thaw one by one as needed.
the freezing of the greiner plates is a bit trickier because you have to
avoid condensation on the sealing film.
this condensation would eventually fall onto the crystallization benches.
but once you have that figured out it is not a problem. there are tricks
for that ...
at present we are using both aluminium sealing film from Axygen (catalog
no. 732-0658) and the ultra-clear sealing film from Axygen (cat. no.
They are both certified to resist from -10 to +100°C, but we found that
the aluminium reacts with a few reagents from the Hampton Xtal Screen,
that's why we use the ultraclear for sealing those screens. We normally
store the screens at 4°C, but they do not last for more than 2 months
(this is our turn-over).
Our policy is to buy the 10ml screens in 14ml centrifuge tubes, and
manually fill in two deep-wells at a time (each one lasts for 10
So we keep the screens in the tubes for as long as possible.
I hope this helped
We use aluminium adhesive seals (PCR seals - ABgene AB0626) since they
are nice and sticky and deform slightly into the well to give a good
seal, but can also be removed quite easily. For long term storage they
go at 4degrees.
The cap-mats are terrible, dont use them since they dont seal very well
and volatiles such as isopropanol will disappear very quickly.
Hope this helps.
Tom Walter B.Sc. M.Res.
Few free to send more comments if you like. Thanks to all again,
Laboratório Nacional de Luz Síncrotron
Cristalografia e Espectroscopia de Biomoléculas
Tel: +55 19 3512 1275