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: "WILLIAM DESALVO" <[email protected]> To: "Paula Sicurello" <[email protected]>, "histonet" <[email protected]>, "[email protected]" <[email protected]> Sent: Wednesday, November 20, 2013 9:58:42 AM 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: [email protected] > To: [email protected]; [email protected] > 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 > [email protected] > http://lists.utsouthwestern.edu/mailman/listinfo/histonet _______________________________________________ Histonet mailing list [email protected] http://lists.utsouthwestern.edu/mailman/listinfo/histonet _______________________________________________ Histonet mailing list [email protected] http://lists.utsouthwestern.edu/mailman/listinfo/histonet
