X-Message-Number: 23640 From: "Basie" <> Subject: mechanical damage by ice crystals is nonsense. Date: Mon, 15 Mar 2004 23:49:11 -0500 It is clear that so called mechanical damage by ice crystals is nonsense. Under certain cold conditions the cell membrane become destabilized. Enzymes then leak out. One can speculate by simple infusing certain specific enzyme inhibitors before freezing enough of the cells can then be recovered in the far future to bring a suspended person back. The Effects of Freezing on Cells in Suspension This section examines the effects of freezing on cells suspended in cryoprotectants, with the special effects of supercooling examined in detail. Vitrification, described in Appendix E , is an alternative approach to cryopreservation which avoids ice formation. The special case of freezing cellular tissues is discussed elsewhere (ovarian and testicular tissue) Following ice nucleation in the suspending medium, cells in suspension are not mechanically damaged by ice nor are they punctured by ice crystals. This is clearly shown in the following video sequence which shows the growth of extracellular ice induced at a low level of undercooling around a human oocyte. This paper can be found at http://www.asymptote.co.uk/process/cryo/cryoguide/report/effects.htm Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=23640