[Histonet] minus 80 freezer safe time in power outage

[Morken, Timothy]

Hi all, For a minus 80 freezer what would you consider a "safe" time period that it can go without power before the temperature gets too high and contents need to be transferred (assuming door stays closed)? I'm thinking -40 would be a cutoff temp to move samples. Anyone else think differently about that?

Thanks for any info!


Tim Morken
Supervisor, Electron Microscopy/Neuromuscular Special Studies
Department of Pathology
UC San Francisco Medical Center
505 Parnassus Ave, Box 1656
Room S570
San Francisco, CA 94143

[phone] (ph)
[phone] (fax)
***@ucsfmedctr.org<mailto:***@ucsfmedctr.org>

[Mitchell Jean A]

Tim: speaking from experience (unfortunately) and the failure of a -80/-70 freezer. As you would imagine once the power goes out or the freezer malfunctions - the freezer temperature rises very quickly. I would estimate, and without opening the door, at the most you have 1-2 hours before you are at -40 and or higher. But if the freezer malfunctions - you usually open the door to check for any ice blockage/build-up that might be causing a poor seal and once you open the door the temp increases very quickly.

When these ultra-low freezers fail you don't have much time to transfer tissue - and usually in the middle of the night.......

Jean Mitchell, BS HT (ASCP)
University of Wisconsin Hospital & Clinics
Neuromuscular Laboratory
600 Highland Avenue
Madison, WI 53792-5132


-----Original Message-----
From: histonet-***@lists.utsouthwestern.edu [mailto:histonet-***@lists.utsouthwestern.edu] On Behalf Of Morken, Timothy
Sent: Friday, March 29, 2013 10:16 AM
To: Histonet
Subject: [Histonet] minus 80 freezer safe time in power outage

Hi all, For a minus 80 freezer what would you consider a "safe" time period that it can go without power before the temperature gets too high and contents need to be transferred (assuming door stays closed)? I'm thinking -40 would be a cutoff temp to move samples. Anyone else think differently about that?

Thanks for any info!


Tim Morken
Supervisor, Electron Microscopy/Neuromuscular Special Studies Department of Pathology UC San Francisco Medical Center
505 Parnassus Ave, Box 1656
Room S570
San Francisco, CA 94143

[phone] (ph)
[phone] (fax)
***@ucsfmedctr.org<mailto:***@ucsfmedctr.org>

[Helen Fedor]

Hello, I think it would depend on what you think the malfunction is due to. If you do not have a solution in sight. I would start thinking about moving them immediately. RNA is sensitive to this type of warming. How long is the transfer going to take? If they already up to -40 they are going to be to -30 when they get to their new destination. And that is a problem.

Helen

-----Original Message-----
From: histonet-***@lists.utsouthwestern.edu [mailto:histonet-***@lists.utsouthwestern.edu] On Behalf Of Morken, Timothy
Sent: Friday, March 29, 2013 11:16 AM
To: Histonet
Subject: [Histonet] minus 80 freezer safe time in power outage

Hi all, For a minus 80 freezer what would you consider a "safe" time period that it can go without power before the temperature gets too high and contents need to be transferred (assuming door stays closed)? I'm thinking -40 would be a cutoff temp to move samples. Anyone else think differently about that?

Thanks for any info!


Tim Morken
Supervisor, Electron Microscopy/Neuromuscular Special Studies Department of Pathology UC San Francisco Medical Center
505 Parnassus Ave, Box 1656
Room S570
San Francisco, CA 94143

[phone] (ph)
[phone] (fax)
***@ucsfmedctr.org<mailto:***@ucsfmedctr.org>

[Maria Mejia]

Hello Tim,

When I worked at UCSF, we had five -80C sub zero freezers stored in a cool room AND on those occasions,
when a freezer did malfunction, our "safe" temperature was -50C - mostly because ALL our frozen specimens
were brain.

We had a protocol in place for checking each freezer (weekly) for ice blockage/build-up on the door
& around the front inside, so as not to create problems w/the freezers...later. However, when a
freezer malfunction did occur it was mostly because of the compressor unit (some freezers have
2 compressors.) When a compressor (or any other part) on a particular freezer was replaced, this
information was always recorded.

In any case, we never opened the door, except to quickly place 1 (5-lb) block of dry ice per shelf, to keep the
low temperature in the freezer constant (overnight) until an outside repair technician could come & make repairs
the next day. **We always kept a large supply of dry ice.

During my 7 years at UCSF, there was only 1 time, we had to transfer all tissue racks into another -80C freezer.
We were very lucky, because we had just purchased a new freezer & the freezer was turned ON the night before.

Tim, I hope this helps. Let me know if you require any further help.

Maria Mejia
Affymetrix, Inc.

Post by Morken, Timothy
Hi all, For a minus 80 freezer what would you consider a "safe" time period that it can go without power before the temperature gets too high and contents need to be transferred (assuming door stays closed)? I'm thinking -40 would be a cutoff temp to move samples. Anyone else think differently about that?
Thanks for any info!
Tim Morken
Supervisor, Electron Microscopy/Neuromuscular Special Studies
Department of Pathology
UC San Francisco Medical Center
505 Parnassus Ave, Box 1656
Room S570
San Francisco, CA 94143
[phone] (ph)
[phone] (fax)
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