Also we had time when finding a non-defrost freezer was difficult and lower temps were not only best; they were about the only way not to have unit turn off and on allowing tissue and antibodies to partially defrost. Some of us learned that the hard way in early days of IHC.
Bill is correct in his answer about why it should be stored at the various temps also. Pam Marcum -----Original Message----- From: histonet-boun...@lists.utsouthwestern.edu [mailto:histonet-boun...@lists.utsouthwestern.edu] On Behalf Of WILLIAM DESALVO Sent: Wednesday, November 20, 2013 9:59 AM To: Paula Sicurello; histonet; microsc...@microscopy.com Subject: RE: [Histonet] -80 degrees rationale 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 > > -- > 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. > _______________________________________________ > Histonet mailing list > Histonet@lists.utsouthwestern.edu > http://lists.utsouthwestern.edu/mailman/listinfo/histonet ---------------------------------------------------------------------- Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message.
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