RE: [Histonet] friable or crumbly O.C.T.
I will 2nd this. When I did neuropathology at a major institution, we froze all frozen sections in an isopentane slurry cooled with LN2. We waited for the OCT to warm to cryostate temps before cutting. If there was time pressure from the surgeons, I used my thumb to warm more quickly, until sections stopped falling apart. We got minimum freeze artifact with this method. For research we used homogenized brain (brain paste) instead of OCT which gave better sections as there was not a change in physical properties you get with OCT vs brain. Bill Blank, MD At 10:40 AM -0400 8/9/10, Della Speranza, Vinnie wrote: >I'm guessing that liquid nitrogen or dry ice temperature is too cold for >sectioning OCT. >OCT cuts well down to about -25 degrees C. >Liquid Nitrogen is about -160 degrees C. I believe dry ice is in the same temp >range at LN2 > >You will want to give the OCT blocks the opportunity to "warm up" to cryostat >temperature before attempting to section them. Leave your frozen blocks in the >cryostat for 30-60 minutes before sectioning to allow them to come to optimum >temperature ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
Re: [Histonet] friable or crumbly O.C.T.
There is an OCT for lower temperatures. - Original Message - From: "Della Speranza, Vinnie" To: "Bruce W Brodersen" , histo...@pathology.swmed.edu Sent: Monday, August 9, 2010 9:40:03 AM Subject: RE: [Histonet] friable or crumbly O.C.T. I'm guessing that liquid nitrogen or dry ice temperature is too cold for sectioning OCT. OCT cuts well down to about -25 degrees C. Liquid Nitrogen is about -160 degrees C. I believe dry ice is in the same temp range at LN2 You will want to give the OCT blocks the opportunity to "warm up" to cryostat temperature before attempting to section them. Leave your frozen blocks in the cryostat for 30-60 minutes before sectioning to allow them to come to optimum temperature Vinnie Della Speranza Manager for Anatomic Pathology Services Medical University of South Carolina 165 Ashley Avenue Suite 309 Charleston, South Carolina 29425 Tel: (843) 792-6353 Fax: (843) 792-8974 -Original Message- From: histonet-boun...@lists.utsouthwestern.edu [mailto:histonet-boun...@lists.utsouthwestern.edu] On Behalf Of Bruce W Brodersen Sent: Friday, August 06, 2010 2:26 PM To: histo...@pathology.swmed.edu Subject: [Histonet] friable or crumbly O.C.T. Anyone have an explanation as to why OCT would be friable or crumbly for sectioning? Here's how it was used. Thanks. "We held the plastic 'tray' with the tissue in the compound just over the liquid nitro for 30sec-1min, until it was opaque and white (frozen) and then dipped the tray into the liquid nitro for 20-30sec., placed in small bags and then into a cooler with dry ice until shipping." Bruce W. Brodersen, DVM, PhD University of Nebraska Veterinary Diagnostic Center 1900 N. 42nd Street Lincoln, NE 68583-0907 voice (402) 472-1434 FAX (402 472-3094___ 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 ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] friable or crumbly O.C.T.
I'm guessing that liquid nitrogen or dry ice temperature is too cold for sectioning OCT. OCT cuts well down to about -25 degrees C. Liquid Nitrogen is about -160 degrees C. I believe dry ice is in the same temp range at LN2 You will want to give the OCT blocks the opportunity to "warm up" to cryostat temperature before attempting to section them. Leave your frozen blocks in the cryostat for 30-60 minutes before sectioning to allow them to come to optimum temperature Vinnie Della Speranza Manager for Anatomic Pathology Services Medical University of South Carolina 165 Ashley Avenue Suite 309 Charleston, South Carolina 29425 Tel: (843) 792-6353 Fax: (843) 792-8974 -Original Message- From: histonet-boun...@lists.utsouthwestern.edu [mailto:histonet-boun...@lists.utsouthwestern.edu] On Behalf Of Bruce W Brodersen Sent: Friday, August 06, 2010 2:26 PM To: histo...@pathology.swmed.edu Subject: [Histonet] friable or crumbly O.C.T. Anyone have an explanation as to why OCT would be friable or crumbly for sectioning? Here's how it was used. Thanks. "We held the plastic 'tray' with the tissue in the compound just over the liquid nitro for 30sec-1min, until it was opaque and white (frozen) and then dipped the tray into the liquid nitro for 20-30sec., placed in small bags and then into a cooler with dry ice until shipping." Bruce W. Brodersen, DVM, PhD University of Nebraska Veterinary Diagnostic Center 1900 N. 42nd Street Lincoln, NE 68583-0907 voice (402) 472-1434 FAX (402 472-3094___ 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
