Embryo freezing
At Equifreeze, we specialize in freezing embryos collected from donor mares so they can be transferred into a recipient mare at a later time.
Here’s how it works: your veterinarian collects the embryo and sends it to our lab. Once the embryo has arrived at Equifreeze, we carefully evaluate the embryo for size and quality and select the most suitable method for freezing.
Most embryos are frozen using a fast-freezing process called vitrification, which helps protect the embryo by preventing ice crystal formation, resulting in higher pregnancy rates. Smaller embryos (usually collected around Day 6.5 to 7 after ovulation) are placed in an appropriate freezing medium containing cryoprotectants to protect the embryonic cells from freezing damage and frozen directly. Larger embryos are first gently collapsed using a sophisticated micromanipulator unit to remove extra fluid, then placed in a medium containing cryoprotectants and vitrified. This additional step helps improve the chances of success. Once frozen, the embryos are safely stored in liquid nitrogen at -196°C—similar to how frozen semen is preserved—until you're ready for the transfer. Embryos can be stored for a long time (years) in liquid nitrogen without any loss of viability.
Because the best results are obtained with smaller, younger embryos, we advise collecting the embryo on Day 7 after ovulation. The preferred day of ovulation should be determined with your veterinarian, who is monitoring the estrous cycle of the donor mare. To perform the embryo collection at the optimal time, the donor mare must be monitored daily while in estrus (heat) so that the exact date of ovulation can be established. At Equifreeze, we are available to advise you and your veterinarian on the optimal monitoring schedule and the best time for embryo collection.
When the embryo is collected, it should be washed and packed as is routinely done for fresh, transported embryos. After washing, the embryo is placed in a sterile 5 ml tube filled with Embryo Holding Medium. The 5 ml tube containing the embryo is sealed with parafilm and placed in a 50 ml tube filled with water at 25°C. This tube is then placed in a transport container with balast packs at 25°C to ensure a stable temperature during transport. The transport container can be shipped with a commercial courier (preferably HippoXpress) to our facility and should arrive within 12 hours after embryo collection.
Because the embryo freezing process takes time and material needs to be prepared, it is necessary to book a possible embryo freezing session on the day that the donor mare has ovulated. This allows us to reserve a slot to handle your embryo correctly. On the day of embryo collection, you or your veterinarian should contact the team at Equifreeze immediately upon completion of the embryo collection to notify us if an embryo will be shipped to us. Failure to contact us will result in billing for lost time and materials, identical to that of a regular embryo freezing procedure.
Once the embryo is frozen, it will be labeled and placed in storage in a liquid nitrogen tank at -196°C. The embryo will maintain its viability for years as long as it has been kept in liquid nitrogen continuously and without interruption. We will store the embryo for up to one year at no additional cost. After this period, a storage fee of 10€/month (excl. VAT) will be charged automatically.
Yes, you can. The frozen embryo can be transported (in an appropriate liquid nitrogen tank) to a storage facility of your choice. Expenses associated with the embryo transport (use of liquid nitrogen transport tank, courier) are at the client’s expense.
Equifreeze does not have facilities to house recipient mares, nor is it equipped to perform embryo transfer. However, our team can provide personalized thawing and transfer service at your facility or a veterinary facility of your choice.
