Cryopreservation

Cryogenically preserved samples being removed from a dewar of liquid nitrogen

Cryopreservation or cryoconservation is a process where biological material - cells, tissues, or organs - are frozen to preserve the material for an extended period of time.[1] At low temperatures (typically −80 °C (−112 °F) or −196 °C (−321 °F) using liquid nitrogen) any cell metabolism which might cause damage to the biological material in question is effectively stopped. Cryopreservation is an effective way to transport biological samples over long distances, store samples for prolonged periods of time, and create a bank of samples for users. Molecules, referred to as cryoprotective agents (CPAs), are added to reduce the osmotic shock and physical stresses cells undergo in the freezing process.[2] Some cryoprotective agents used in research are inspired by plants and animals in nature that have unique cold tolerance to survive harsh winters, including: trees,[3][4] wood frogs,[5] and tardigrades.[6] The first human corpse to be frozen with the hope of future resurrection was James Bedford's, a few hours after his cancer-caused death in 1967.[15] Bedford's is the only cryonics corpse frozen before 1974 still frozen today.

  1. ^ Hunt, Charles J. (2017), Crook, Jeremy M.; Ludwig, Tenneille E. (eds.), "Cryopreservation: Vitrification and Controlled Rate Cooling", Stem Cell Banking: Concepts and Protocols, Methods in Molecular Biology, vol. 1590, New York, NY: Springer, pp. 41–77, doi:10.1007/978-1-4939-6921-0_5, ISBN 978-1-4939-6921-0, PMID 28353262, retrieved 2023-01-08
  2. ^ "Cryoprotective Agent - an overview | ScienceDirect Topics". www.sciencedirect.com. Retrieved 2023-01-08.
  3. ^ "How do trees survive the winter?". www.nationalforests.org. Retrieved 2023-01-08.
  4. ^ Cavender-Bares, Jeannine (2005-01-01), Holbrook, N. Michele; Zwieniecki, Maciej A. (eds.), "19 - Impacts of Freezing on Long Distance Transport in Woody Plants", Vascular Transport in Plants, Physiological Ecology, Burlington: Academic Press, pp. 401–424, doi:10.1016/b978-012088457-5/50021-6, ISBN 978-0-12-088457-5, retrieved 2023-01-08
  5. ^ "Antifreeze-Like Blood Lets Frogs Freeze and Thaw With Winter's Whims". Animals. 2007-02-20. Archived from the original on March 2, 2021. Retrieved 2023-01-08.
  6. ^ Mayer-Grenu, rea; Stuttgart, University of. "How tardigrades survive freezing temperatures". phys.org. Retrieved 2023-01-08.