X-Message-Number: 11790 Date: Thu, 20 May 1999 11:16:17 -0700 (PDT) From: Doug Skrecky <> Subject: freeze-drying In Message #11780 wrote: >The main disadvantage--of either freeze-drying or chemical fixation, or a combination--of course is just the fact that viability (as currently observed or measured) is virtually nil at the level of mammalian tissues, in the context of current capabilities. This may be more of a psychological problem than a scientific problem, in the context of future technology. Logically, a sufficient degree of preservation of structure is all that is necessary, with preservation of function pretty much irrelevant--but that is a hard sell indeed, even to most committed cryonicists. < Liquid-drying may be a way around this. Organisms that undergo anhydrobiosis use a variant of this method to survive complete desiccation. Experiments with freeze-intolerant bacteria have found that this can preserve viability, when adequate protection against free radical damage is provided. Human application of this would need some basic research done first. Freeze-drying is always going to be at least as damaging as freezing. Liquid-drying avoids this. >Another possible disadvantage might be cost of preparation. Freeze-drying something as large as a human, by any currently used methods, is a very slow process, and therefore an expensive one. We have some ideas to offset this, but so far we cannot see our way to giving this project a high priority. A higher level of research donations could change this. < I suggest that the most cost effective start for any research program into any type of drying preservation would be to complete a search of past experiments in this field. Only after reading and analysing all of the existing relevant data on the topic could a practical, affordible experimental program be devised. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=11790