Fig. 2.

Use of oocyte specific cryoprotectants, aimed at addressing oocyte membrane permeability characteristics and other unique physiologic properties, is critical in optimizing outcomes. Similarly, consideration to oocyte requirements should be given selecting the basal media formulation, including substrate and salt composition. Though use of a single basal media and cryopreservation system for preimplantation embryos of various stages and oocytes may be convenient, conditions should be optimized based on the physiology of the oocyte