title: Liquidus tracking: controlled rate vitrification for the cryopreservation of larger volumes and tissues.
abstract: BACKGROUND
  Vitrification of cells or tissue at controlled cooling rates suitable for larger volumes, and with reduced cryoprotectant toxicity.
  
  
  OBJECTIVE
  To set out the current understanding of the LiquidusTracking (LT) vitrification technique, and to discuss the challenges and benefits of translating the method into laboratory protocols more generally applicable to meet requirements of large volume and 3-D cryo-banking in the era of regenerative medicine.
  
  
  METHODS
  By adding small amounts of cryoprotectants at each step and subsequently cooling the sample just above its freezing point before further increasing CPA concentration, cryoprotectant toxicity is minimized.
  
  
  RESULTS
  CPA toxicity can be reduced by lowering the temperature. Different manual approaches to LT were evaluated and further improved.
  
  
  CONCLUSIONS
  Manual liquidus tracking is complicated and exhibits potential high variability. Nevertheless, this approach offers the possibility of testing several conditions simultaneously and could be used to pre-test conditions prior to automatic LT development.
authors.affiliation: UCL, Institute for Liver and Digestive Health, Royal Free Campus, London, UK. eva.puschmann.10@ucl.ac.uk.
authors.forename: E
authors.initials: E
authors.lastname: Puschmann
authors.affiliation: UCL, Institute for Liver and Digestive Health, Royal Free Campus, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Selden
authors.affiliation: Planer PLC,110 Windmill Road, Sunbury-on-Thames, UK.
authors.forename: S
authors.initials: S
authors.lastname: Butler
authors.affiliation: UCL, Department of Surgery, Royal Free Campus, London, U.K.
authors.forename: B
authors.initials: B
authors.lastname: Fuller
mesh_terms: D000464:Alginates / Q000737:chemistry; D018914:Cells, Immobilized; D015925:Cryopreservation / Q000295:instrumentation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D020723:Glucuronic Acid / Q000737:chemistry; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D007053:Ice / Q000032:analysis; D008099:Liver; D008954:Models, Biological; D046509:Tissue Culture Techniques; D014021:Tissue Preservation; D058989:Vitrification
chemical_list: D000464:Alginates; D003451:Cryoprotective Agents; D006603:Hexuronic Acids; D007053:Ice; D020723:Glucuronic Acid