General principles of cryopreservation.

Cryopreservation quickly became a cornerstone technology in assisted reproduction because the banking of gametes, embryos, and gonadal tissues has increased the effectiveness of assisted reproductive technology cycles for infertility treatment as well as fertility preservation for patients at risk of premature sterilization. Cryopreservation protocols, both slow/equilibrium cooling and vitrification methods, have evolved empirically and still depend heavily on operator skill, but further automation promises to improve reproducibility and uniformity of results.