Chapter 14 - Cryopreservation of spermatozoa

Summary

Cryopreservation of male and female gametes has been long established, and nowadays low-temperature storage of human spermatozoa is a routine technique in assisted reproduction. The vitrification method uses no specially developed cooling program; it does not need to apply permeable cryoprotectants; it is much faster, simpler and cheaper; and it can also provide a high recovery of motile spermatozoa after warming as effective protection of spermatozoa against cryodamage. Higher concentrations of cryoprotectants are needed for extracellular than for intracellular vitrification. The success of Luyet's vitrification technique was supported by Shaffner applying the technique to frog spermatozoa after vitrification of fowl sperm. The advantage of programmable or non-programmable conventional slow freezing is the ability to simultaneously preserve a relatively large volume of diluted ejaculate or prepared spermatozoa. Long-term storage of frozen cells and tissues remains elusive in both theoretical and routine cryobiology, and future investigation applying nanotechnology is needed.