I know people are going to think I have stock in "Bitran" but really I
don't. I just know the product works for maintaining integrity of the OCT
over a long period of time. I use the "Bitran" bags to store my OCT blocks
at -70C for years. I get very little if any freeze dry affect on the OCT.
(all depends on length of time) Cover the tissue with OCT put in bag remove
excess air, seal. I have sectioned the blocks after two years and still get
antibody staining. (fibronectin and smooth muscle actin staining are very
comparable to the original cut) It all depends on what you are looking for.
Controls are a must. Sometimes the block needs a little trimming around the
edges but the tissue does not look lyophilized. My theory has always been
storing in block form is preferable to storing in section form if at all
possible.
I get the bags from Com-Pac International but I think some of the bigger
companies carry them (Fisher, Baxter etc.). Com Pac can tell you who handles
their product on a big scale (i.e. cheaper than direct) their phone number
is 800-824-0817 and they are in Carbondale IL. I not only store blocks in
these bags, I also use them for storing slides. I put them in slide boxes
and then put the boxes in Bitran bags, which are air tight and liquid tight.
You can put the desiccant in the bag instead of near the slides. These can
be stored for at least a month with no adverse affects on the tissues I have
used. I don't get any ice crystals from humidity on the slides. Let me know
if you need more details. anita

>
> -----Original Message-----
From: Michael Stumm [mailto:stumm@ubaclu.unibas.ch]
Sent: Wednesday, September 22, 1999 9:25 AM
To: histonet@pathology.swmed.edu
Subject: long time storage of frozen tissue


Dear Histonetters

 I would like to keep collected tissue specimens in a -70°C fridge in order
to make frozen tissue sections on demand. Can you provide me with some
comments about methods for long time storage of frozen tissue specimens?

Thank you.

Michael

Michael Stumm, MD, Lab 405
Department of Research
Kantonsspital Basel
Hebelstrasse 20
4031 Basel
Switzerland
phone: ++41/61/265 23 84
email: stumm@ubaclu.unibas.ch