[Histonet] RE: minus 80 freezer safe time in power outage

[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-bounces <@t> lists.utsouthwestern.edu [mailto:histonet-bounces <@t> 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

(415) 353-1266 (ph)
(415) 514-3403 (fax)
tim.morken <@t> ucsfmedctr.org<mailto:tim.morken <@t> ucsfmedctr.org>

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