Several procedures in embryology require the cryopreservation of whole sperm samples or of isolated sperm cells. These include sperm banks that freeze sperm samples from sperm donors, freezing of sperm found during advanced sperm searches in samples from azoospermic men. Freezing of sperm must be handled by qualified lab personnel, and then kept at highly controlled conditions in dedicated equipment. Sperm can be kept cryo frozen for many years.
