The Use of Ultrarapid Freezing and Freeze Substitution to Verify Vitrification and/or Ice Formation in Vascular Tissue

Abstract

Abstract The expanding field of cryobiology, in particular that of the study of vitrification for long term storage of tissues for transplantation, has demonstrated that ice is damaging to smooth muscle tissue. Consequently conventional methods such as ultrarapid freezing and freeze substitution are becoming routine protocols to determine the quality of cryopreservation. This article introduces the scientific community to the PS-1000 cryofixation unit (Delaware Diamond Knives, Wilmington, DE) which provides both ultrarapid freezing and a means of validation of freeze substitution methods. When any tissue is frozen or vitrif ed for clinical use it is imperative to know the structural and functional integrity of these tissues. Ice formation within the extracellular matrix and dehydration of multi-cellular tissues, using conventional cryopreservation, is the principal reason why these methods frequently prove to be ineffective.