CRYOSIM - A USER-FRIENDLY PROGRAM FOR SIMULATING CRYOPRESERVATION PROTOCOLS

Models of cryopreservation are valuable research tools, but developmen t of models for widespread use has been hindered by the difficulty of writing reliable and user-friendly computer code and interpreting comp uter output when the fundamental equations are based on complex modeli ng assumptions. These obstacles have been surmounted in Cryosim, a pro gram for simulating water and cryoprotectant additive (CPA) flux durin g cryopreservation using the two-compartment model for chemical transp ort, the Kedem-Katchalsky model for membrane permeability, the Arrheni us function for changes in permeability with respect to temperature, a nd functions for phase diagrams of water, sodium chloride, and either glycerol or dimethyl sulfoxide published by Pegg. Cryosim assumes an i sothermal system with well-mixed, ideal solutions that follow equilibr ium phase diagrams. The only permeable species are water and CPA, and passive diffusion is the only transport process. The program is best s uited for simulating cryopreservation of single cells or microscopic t issues such as embryos and pancreas islets at slow or moderate cooling and warming rates. Cryosim calculates supercooling and solute concent rations for both interior and exterior solutions, system temperature, and Volume relative to isotonic. Cryosim can be obtained from the auth or at no charge starting in January, 1994. It runs on any IBM-compatib le PC with 640K of RAM and uses less than 0.5 MB of hard disk space. R equests should be sent by E-mail to dwalcerz@wpi.wpi.edu or by post. ( C) 1995 Academic Press, Inc.