Mouse Embryos & OocytesMouse Embryos & Oocytes High quality cryopreserved mouse embryos & oocytes with a Simple One Step Thawing Process. Frozen blastocyst embryos are at Early Blastocyst Stage upon freezing. If you are looking to obtain full blastocyst or expanded blastocyst, you will need to culture upon thaw to achieve this. Mouse embryos can be used for the production of research models, conducting Quality Control Testing such as MEA (Mouse Embryo Assay), embryo