Vitrification and devitrification of ovules and embryos

The vitrification of eggs and embryos is a technique that allows them to acquire a state similar to glass, using cryoprotectants, mainly dimethyl sulfoxide (DMSO), which, in a very small volume, solidifies by rapid cooling, by extreme elevation of its viscosity, followed by freezing. fast in immersion in liquid nitrogen.

The high osmolarity of the vitrification solution allows cell dehydration and therefore intracellular water does not have time to form crystals and injure intracellular organelles, the freezing rate is 15,000-30,000 °C/min.

The vitrification of oocytes or embryos is very useful for women who need to defer the possibility of becoming pregnant.

For example, due to premature ovarian failure, cancer treatments, postponing pregnancy due to working life, elevated ovarian stimulation responses, religious ideals, that is, in many aspects of the daily life of patients.

Fertilización In Vitro En Puebla y Veracruz

Egg or embryo devitrification (Thawing).

Devitrification is a process that consists of thawing the eggs or embryos that were stored in a tank containing liquid nitrogen, so they will go from a temperature of -196°C to a body temperature of 37°C, the embryos are incubated in media of specific conditions, with high concentrations of other more dilute media progressively.

Cell rehydration.

Cellular rehydration will gradually replace the presence of cryoprotectants with water until it acquires a turgid appearance. They will be incubated for a period of 2 to 5 hours.

“Generally, the devitrification of eggs and embryos is performed the same day as the fertilization procedure or the embryo transfer, respectively, a few hours apart.”

Biol. Luis Machorro
Biol. Luis Machorro
IVF and Andrology Laboratory

Vitrification of eggs and embryos at the Mexican Institute of Infertility.

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