X-Message-Number: 1925 Date: Tue, 9 Mar 1993 17:51:35 MST From: "Richard Schroeppel" <> Subject: CRYONICS: High Temperature Storage Problem: Biological tissues cooled much below the glass transition temperature crack, making reconstruction difficult, and possibly losing important ultra-structural information. Solution: Only freeze the tissue cold enough to inhibit bacterial growth, and slow down enzymatic degradation. Micro-pockets of water will remain in the liquid state, but if they are small enough, we don't care. A few enzymes will do a small amount of damage, but the total damage is much smaller than pervasive cracking. Any enzyme promoting an endothermic reaction will stop immediately due to lack of ATP. If the tissue is mostly ice, then no significant diffusion will take place, so all enzymes should run out of reactants pretty quickly. If a few enzymes are responsible for damage, then we can look for inhibitors, and administer them during cool-down. If the bulk structure of the tissue is solid, and enough of the cell walls survive that synapse positions can be determined, then there's a possibility of a nanotech reconstruction. Perhaps -50C would be a reasonable temperature. Rich Schroeppel Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=1925