The only way to really know is to validate the temperature for the samples you want to store. The acceptable range must meet the performance of the unit and be in an acceptable range for any manufactureg materials stored in the freezer. All this will be tied up in your SOP.
William DeSalvo, BS HTL(ASCP) Date: Wed, 20 Nov 2013 12:37:01 -0500 Subject: Second Question of the Day: -80 degrees rationale From: pat...@gmail.com To: wdesalvo....@outlook.com CC: histonet@lists.utsouthwestern.edu; microsc...@microscopy.com Hello Again, Gayle and Bill have provided the most succinct answers to the question of the day. Second Question: Is there a lower end, say -70 or -75, that provides the same protection as -80? I'm asking all this because I've inherited an old -80 freezer and would like it to last as long as possible. The lab that had this freezer previously had an acceptable range of -70 to -90. Thanks in advance, again, oh wise ones. Paula -- > Paula Sicurello, HTL (ASCP) > Supervisor, Clinical Electron Microscopy Laboratory > Duke University Health System > Rm.#251M, Duke South, Green Zone > Durham, North Carolina 27710 > P: 919.684.2091 > > HIPAA Privacy Notification: This message and any accompanying documents are > covered by the Electronic Communications Privacy Act, 18 U.S.C. 2510-2521, > and contain information intended for the specific individual (s) only. This > information is confidential. If you are not the intended recipient or an > agent responsible for delivering it to the intended recipient, you are > hereby notified that you have received this document in error and that any > review, dissemination, copying or the taking of any action based on the > contents of this information is strictly prohibited . If you have received > this communication in error, please notify us immediately by e-mail, and > delete the original message. On Wed, Nov 20, 2013 at 10:58 AM, WILLIAM DESALVO <wdesalvo....@outlook.com> wrote: Here is my stab at why -80 C. Temperatures between 0°C and −25°C, the enzymatic activity of cells is only slowed but remains active. Below −40°C physiochemical exchanges are frozen. Cellular morphology is preserved at -80°C. Shelf life of tissue increases as the temperature drops. Once you get below -80°C you will need cryoprotectors and when you use cryoprotectors, temperatures must be below −130°C and will go as low as −196°C (liquid nitrogen). Antibodies and proteins in solution are stable at −20°C. William DeSalvo, BS HTL(ASCP) > Date: Wed, 20 Nov 2013 09:25:54 -0500 > From: pat...@gmail.com > To: histonet@lists.utsouthwestern.edu; microsc...@microscopy.com > CC: > Subject: [Histonet] -80 degrees rationale > > Hello My Fellow Listers, > > The question of the day is: What is the rationale for storing frozen > biopsies at -80 degrees? > > I have seen protocols that range in temperature from -40 to -80 degrees. > > Was -80 selected because that was the lowest freezers could go back in the > day? > > Awaiting your chilly responses! > > Thanks in advance, > > Paula > >> _______________________________________________ > Histonet mailing list > Histonet@lists.utsouthwestern.edu > http://lists.utsouthwestern.edu/mailman/listinfo/histonet -- Paula Sicurello, HTL (ASCP)Supervisor, Clinical Electron Microscopy LaboratoryDuke University Health SystemRm.#251M, Duke South, Green Zone Durham, North Carolina 27710P: 919.684.2091 HIPAA Privacy Notification: This message and any accompanying documents are covered by the Electronic Communications Privacy Act, 18 U.S.C. 2510-2521, and contain information intended for the specific individual (s) only. This information is confidential. If you are not the intended recipient or an agent responsible for delivering it to the intended recipient, you are hereby notified that you have received this document in error and that any review, dissemination, copying or the taking of any action based on the contents of this information is strictly prohibited . If you have received this communication in error, please notify us immediately by e-mail, and delete the original message.
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