I really do not know of any study comparing -20ºC vs -80ºC or if this -80ºC is the result of a commercially driven "ideal" storage method. I advise you to check about any bibliographic references BUT meanwhile I also advise you to keep your precious and irreplaceable material at -80ºC. I do not think that you should risk losing all your samples just to work "on the cheap". I always kept my tumor bank and IF samples at -80ºC and when our freezer also died year ago, I was lucky enough to get the approval to buy a new one. Do not rush to save money René J.
________________________________ From: DAVID HENDERSON <dhender...@msn.com> To: "histonet@lists.utsouthwestern.edu" <histonet@lists.utsouthwestern.edu> Sent: Sunday, November 10, 2013 6:56 PM Subject: [Histonet] Frozen IF Specimen Storage: Is -80 C really necessary; will -20 C work? We routinely store our frozen IF specimens (renal and skin biopsies) embedded in OCT and sealed in plastic bags for at least 4 yrs in a -80C freezer. Cases that are positively diagnosed by the pathologist, are used as positive controls for subsequent IF staining. In practice, most positive controls are used within 1-2 years of their original storage. Our -80C freezer has died, and we are temporarily storing in a different -80C freezer in another building on campus. My supervisor asked me to research whether or not a -20C freezer will suffice for our storage needs, or must we anti up for the much more costly -80C replacement or repair. I would appreciate receiving suggestions backed by experience, or educated thoughts about the advisability of -20C storage of specimens for future IF staining. Thanks, David Henderson, HTL RML, Tulsa, OK _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet