This course begins with a basic review of the principles of physics that occur during first-order (freezing/thawing) and second-order (vitrification/warming) phase changes. We will present a simplistic model to understand the phase change based on water, subsequently introducing solutes, cell systems and finally, the addition of cryoprotectants by analyzing the effect on the cell suspensions that we want to freeze.  We will introduce different techniques for cryopreservation of gametes, embryos and tissues, reviewing the classical methods of freezing (equilibrium methods) and vitrification (non-equilibrium methods).

We will study in a comparative way the advantages and disadvantages of each methodology and the repercussions on the nature of the elective specimen to be cryopreserved.  We will consider the current trends in cryopreservation of gametes, embryos and reproductive tissues presenting ethical, technical, legal and logistical limitations, as well as referenced efficiencies.