X-Message-Number: 8299 Date: Mon, 9 Jun 1997 08:29:01 -0700 (PDT) From: Doug Skrecky <> Subject: interesting bit on fractures The incidence of fractures in cryopreserved arteries has been found to be sensitive to the rewarming rate. Arteries cooled at 1 C/min to -80 C, then cooled rapidly by transfer to nitrogen gas at -180 C had a zero fracture rate when warmed slowly to -100 C, before being placed in 37 C water. When this transfer occurred at -120 C the fracture rate was 35%. When the transfer occurred at -140 C the fracture rate was further increased to 89%. This rewarming rate dependance of fracturing has been ascribed to the glass transition of -123 C of the DMSO cryoprotectant which was used making the arteries very fragile at this temperature. After slow warming to -100 C had softened the glass, fractures do not occur regardless of the rewarming rate. Reference: "Fractures in Cryopreserved Elastic Arteries" Cryobiology 34: 183-192 1997 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=8299