X-Message-Number: 23350 From: "Basie" <> Subject: Cryopreservation at high pressure Date: Sat, 31 Jan 2004 22:36:18 -0500 Abstract This study compared 4 fixation methods of rabbit articular cartilage. Tibial plateau samples were prepared either by chemical fixation, with or without microwave enhancement, freezing at ambient pressure followed by freeze substitution or high pressure freezing methods. Following the initial preservation, samples were freeze fractured to expose their internal structure. Microwave enhanced chemical fixation provided preservation of the morphological structure within seconds. Conventional immersion fixation required hours to give comparable preservation. Ambient pressure cryofixation preserved samples in their hydrated stage within seconds and the subsequent freeze substitution required 10 days. The collagen structure was qualita-tively as well preserved as by the other methods, but the chondrocytes showed severe ice crystal damage. The shrinkage of the samples cryo fixed at ambient pressure was significantly less than conventional or microwave methods.Cryo preservation at high pressure resulted in matrix preservation that was presumably closest to the in vivo state.Collagen fiber structures were difficult to differentiate,which may be due to the presence of frozen hydrated proteoglycans throughout the tissue. Each technique available to preserve cartilage has it's advantages and disadvantages and the methods best suited for the specific research goal must be chosen. Scanning Microscopy Vol. 13, No. 1, 1999 (Pages 61-69) 0891-703599$5.00+.25 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=23350