ANSC 3323 Lecture Notes - Cryopreservation, Cryoprotectant, Supercooling
Document Summary
Lowering temperature of freezing chamber in controlled stepwise manner. Numerous steps involved in conventional slow freezing. Plunge and store in liquid nitrogen (-196 c or -320 f) Process of chilling a liquid below its freezing point without it becoming solid. Glass-like solidification without formation of crystalline structures. Either by the quick removal or addition of heat, or by mixing with an additive. Achieved by high cooling rates in solutions containing concentrations of cpa. Adding cryoprotectants to water prevents water molecules from gathering to form ice. Instead of freezing, molecules just move slower and slower as they are cooled. When the temp drops below 100c very rapidly, molecules become locked in place and a solid is formed. Water that becomes solid without forming ice is vitrified". No ice formation during the cooling, storage, or warming. High concentrations of both permeating and non-permeating cpas. Cells are osmotically dehydrated prior to cooling by equilibration in highly concentrated cpa (>6m)
