X-Message-Number: 24524 Date: Tue, 17 Aug 2004 07:18:27 -0400 From: Thomas Donaldson <> Subject: reply to Coetzee A reply to Coetzee: I'm not surprised at all by your reference, though I am surprised that you gave it. Our organs may consist of single cells, but they are not single cells. Means to freeze most single cells or cultures of single cells have existed for some time, though the variety of cells for which this treatment works has been expanding (there was a time when not every kind of blood cell could be preserved by freezing). Work with single cells has relatively little bearing on freezing whole organs or, for that matter, freezing whole people. It's at THAT level that you get lots of mechanical damage. Yes, we will probably have to adjust our vitrification solutions to deal with nervous tissue, but so far (insofar as its been done, which is hardly very much) even freezing for neural tissue has gone far enough that we can't expect any serious chemical damage. Moreover, by previous precedents with cell suspensions of many kinds, any such damage will probably turn out to be of a kind that we can quickly work out how to avoid. (By chemical damage I include damage to membranes other than by such mechanical factors as ripping them apart). Not that we really want to freeze nervous tissue in the first place. Best wishes and long long life for all, Thomas Donaldson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=24524