Protocols and recommendations for egg devitrification.

It is a rapid, optimized and straightforward technique. The success of the procedure lies in the strict monitoring of the protocol, especially at the critical points for the survival of the oocytes.
In the KITAZATO THAWING MEDIA VT 802 (ref. 91182) - OPEN SYSTEM devitrification protocol you will find the whole procedure with thorough step-by-step indications.

In order to optimize the process and achieve better thawing results, the team of embryologists at OXX bank will provide you with indications and tips enabling you to successfully overcome the different critical points of the technique.

  • The cryotop ALWAYS has to be submerged in liquid nitrogen. Take care with the transition from the tank to the cooling rack and during the withdrawal of the cap from the cryotop straw.
  • Heat the TS medium tube and the plate in the incubator separately > 2 hours (ideally overnight).
  • Temper DS and WS at 25ºC-27°C (ambient temperature) for one hour.
  • It is very important for the TS thermal shock to occur at 37°C (never lower). It is essential to perform a temperature control of the medium to ensure the optimal temperature when submerging the cryotop in TS.

Be careful with the following:

  • • The temperature decreases rapidly when the lid of the Petri dish is lifted. Bear this in mind during the temperature control (37°C should be the actual temperature of the middle of the dish outside the incubator, once the lid has been lifted). Lift it at the same time as the straw is submerged.
  • Rapid, immediate immersion of the cryotop in TS (37°C) in < 1 second. Due to the cryotop’s low volume of loading medium, if the time is greater than one second, the heating rate will not be high enough for adequate survival.
  • • During the first minute in TS the oocyte should detach itself from the cryotop straw. After one minute there are different strategies to obtain it (in this order):
    1. Rub the cryotop straw against the bottom of the Petri dish (on the side without the oocyte) until the oocyte is released from the straw.
    2. Pour medium over the oocyte using a stripper, without touching it with the end of the capillary.
    3. Gently pull the side of the cryotop blade with the capillary, causing it to vibrate and release the oocyte.
  • The oocytes are extremely sensitive during the process and therefore:
    • Handle them as little as possible and always with the greatest care.
    • o Use capillaries of a sufficient diameter to minimize potential damage to the oocyte (greater than 170μm)
  • • Incubate the oocytes at 37°C for 2 hours before the ICSI.

Preparation and realisation

Tips and advice

Useful information

This website uses its own cookies, techniques that are essential for browsing. Also analytical cookies to monitor users and to improve your browsing experience on our website. If you click "Accept all" you are accepting the installation of all cookies. You can also configure cookies according to your preferences by clicking on the "Configuration" button. For more information, please access our cookies policy.   More information.