Sharon, I used to freeze rabbit hearts (a LITTLE bigger than rat) this way.
Pour isopentane into a metal beaker inside a styrofoam container filled with liquid nitrogen to part way up the sides of the beaker. When the isopentane starts to freeze on the bottom of the beaker it is ready. Place cross sections of fresh tissue (or the whole rat heart) on a round of cork with gum tragacanth, orienting it to the way you may be sectioning it if that's its destiny. With a LONG forceps or hemostat, lower cork round, heart side up, into the isopentane. It's important to lower the tissue slowly to prevent cracking but not so slow as to cause freeze artifact. Complete freezing will only take a couple minutes if that. To section tissue, if that's the next step, freeze the bottom of the cork round onto a chuck using OCT. In this way, you insulate the tissue from the RT or cold OCT preventing any chance of thawing of your tissue. Hope this helps you in your situation, Linda A. Sebree University of Wisconsin Hospital & Clinics IHC/ISH Laboratory DB1-223 VAH 600 Highland Ave. Madison, WI 53792 (608)265-6596 -----Original Message----- From: histonet-boun...@lists.utsouthwestern.edu [mailto:histonet-boun...@lists.utsouthwestern.edu] On Behalf Of Shaw, Sharon Sent: Thursday, April 22, 2010 10:06 AM To: histonet@lists.utsouthwestern.edu Subject: [Histonet] Frozen Rat Heart Does anybody have a protocol on freezing rat heart that you can share with me. Thanks, Sharon _______________________________________________ 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