Frequently Asked Questions: VitriFreeze / VitriThaw

FAQ1: Does the volume of T1 really has to be 1mL?
A large volume is needed (500µl is also sufficient). It is important that the tip of the straw is moved when plunged in the medium and the dish is shaken at the same time. This to avoid decreasing temperature around the embryo (avoid recrystallization and aggregation of lethal ice crystals). For the other media, 250µl is sufficient.

FAQ2: Can a dish be re-used after 1 procedure?
Yes, a dish can be used 5 times for the same patient. After this, a new dish should be prepared. Never use the same dish for different patients!

FAQ3: Do reagents need to be warmed in a CO2 incubator?
No, only to 37°C in a standard incubator.

FAQ4: Does every step have to be performed at 37°C?
Yes. Cell membranes are more permeable at 37°C, resulting in an easier uptake of cryoprotectants in a shorter period of time. There are only two vitrification steps with this protocol, leaving the embryo very sensitive. To improve chances it is strongly advised to perform this protocol at 37°C.