X-Message-Number: 14809 From: Brent Thomas <> Subject: re: Frozen Frogs -- not so interesting after all Date: Tue, 31 Oct 2000 11:24:04 -0500 Brian Wowk made a connection that I didn't see in the earlier article...sadly these frogs were not deep frozen but only lightly frozen -- still a better "whole organism" response than we see in the larger mammals (i.e. dogs/pigs) but sadly not quite where we need to be for long term storage without freezer burn. From: Brent Thomas Sent: Tuesday, October 31, 2000 11:19 AM To: '' Subject: RE: Frozen Frogs you know i did wonder about that a bit... from the article it quotes: Soon, Ken Storey of Carleton University will put them in the freezer and they will become curvy, amphibian mounds of ice, hard as rock, with no heartbeat, no other sign of life. It appears I was mistakenly equating "hard as rock" with "frozen solid" (ie deep frozen) but thats kind of why i posted it to the group...for comment and explanation. still i do wonder if the "endogenous cryoprotectants" might still provide better functional protection than applied cryoprotectants (which was the basic thrust of my comment on the story). thanks for the comment! -----Original Message----- From: Brian Wowk [mailto:] Sent: Tuesday, October 31, 2000 11:22 AM To: Subject: Frozen Frogs Dear Mr. Thomas, Re your CryoNet message today: Ken Storey's frogs are not "frozen solid". They are at temperatures only a few degrees below 0'C. Much of the water in these animals remains in the liquid state (its freezing point having been depressed by endogenous cryoprotectants). Chemistry still goes on at these temperatures, and these frogs cannot survive indefinitely in this state. If you cooled them to a temperature at which chemistry truly stops (below -100'C) they would most certainly die. It's a bit of a stretch to argue that Frog's protective strategies will be useful for achieving anything other than perhaps extended *short term* preservation of organs. Long-term preservation of complex organs cannot be achieved by freezing because the amount of ice that forms at deep sub-zero temperatures is fundamentally incompatible with whole organ recovery. ----Brian Wowk Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=14809