Patent ID: 8623658

Claim:
A method of cryopreserving sperm cells comprising: adding a cryoprotectant to a quantity of sperm cells; cooling said quantity of sperm cells and said cryoprotectant to a holding temperature in a range of about 0-8° C.; maintaining said sperm cells and said cryoprotectant substantially at said holding temperature for a period of less than 60 minutes; and supercooling said quantity of sperm cells to a temperature in the range of about −80° C. to −40° C., wherein the step of supercooling said quantity of sperm comprises cooling the sperm cells at a first cooling rate to a temperature that approaches a critical temperature zone at which ice crystal formation and changes in osmotic pressure damage sperm cells and then cooling the sperm at a second cooling rate faster than said first cooling rate through said critical temperature zone.