Cryopreservation of embryos : a way to reduce the number of housed animals and the genetic drift.

The GIGA Mouse facility platform has recently improved its mouse line cryopreservation technique.
The method of embryo cryopreservation by rapid cooling also called aseptic vitrification has been
selected. Vitrification media, key steps and timing have been optimized and validated.
After a first partial exposition of the embryos to cryoprotective solutions, they are immersed in a
vitrifying mixture of penetrating and non-penetrating cryoprotectants for a short time. The straw containing the embryos is immediately sealed before to be plunged in LN2, resulting in a brutal solidification in which crystallization does not have time to occur.