Oocyte Slow Freezing Protocol

Cryopreservation of human oocytes is a valuable technique for the treatment of infertility, resolving legal, ethical, and moral issues related to embryo cryopreservation (1–2). It also preserves the female reproductive potential endangered by pathologies or other conditions. Here, we describe an oocyte cryopreservation technique based on slow freezing-rapid thawing with differential sucrose concentration (0.2 M in the freezing stage–0.3 M in thawing stage) (3), describing the technique in detail with methods, management, organization, and safety of oocyte cryopreservation.