A bank of ovules is a dependence of assisted reproduction clinics that aims at freezing and storage of ova in order to use in assisted reproduction techniques such as in vitro fertilization. The ovules are stored in special containers. The receipt of donated ova is, for some women, the only option for mothers, and it is possible because there are donors who voluntarily decide to lease its ovules. Besides donor ova storage, preservation of frozen ova is useful when the patient is to undergo cancer treatment (producing damage in the ovaries ) when you want to postpone motherhood or when you need to accumulate ovules because it has a low response ovarica. Unlike sperm, which can be frozen without loss of quality, the eggs produce ice crystals can destroy the cell inside. This situation has gotten reversed with the technique of vitrification.