**1. Introduction**

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pp. 335-346

The proposed chapter investigates methods, devices and technologies for cryopreservation, explaining the most used cooling processes, as well as conventional and innovative technologies adopted. Main processes used for cryopreservation of oocytes, embryos and sperms can be reassumed in three categories:


Research is not intended to be exhaustive, but is aimed at covering most of relevant topics.

Slow freezing involves step-wise programmed decrease in temperature. The procedure is lengthy and requires the use of expensive instrumentation. The process does not exclude ice crystal formation, which can have extremely deleterious effects (Pegg, 2005).

In the vitrification process, the use of CryoProtectant Agents and the increasing of cooling rate (from 2,500 ◦/min to 130,000 ◦/min) avoid the ice crystal formation, increasing the embryos and oocytes survival. Unfortunately, common cryoprotectants are toxic and the immersion of solution directly in liquid nitrogen can be cause of contamination of embryos and oocytes with bacterium, mushroom and virus.

Ultra-rapid freezing can be considered a midway technique between slow freezing and vitrification, but its application has demonstrated lower performances than the other two processes.
