Prenatal Mouse Embryos Retrieval: A Procedure to Harvest Embryos from Pregnant Mouse

Mouse embryos are used as model systems for studying early mammalian embryogenesis. To retrieve perinatal mouse embryos at the desired stage of embryonic development,  begin with a euthanized pregnant mouse in the supine position.

Next, sterilize its abdominal area and make a transverse incision on the abdominal wall to reveal the underlying uterine horns. The uterine horns are long tubular structures containing a string of embryos. Now, carefully separate the uterine horns from the abdomen by excising them from the surrounding tissue.

Transfer the harvested uterine horns into a dish containing buffer. Rinse the uterine horns to remove tissue debris and blood. Further, incise between the implantation sites along the uterine horns to separate each embryo. Excise the decidua, the maternal placental layer, along with the embryo-derived placental disc.

Next, remove the small extraembryonic membranous structure surrounding the embryo that provides nutrition to it - the yolk sac. Finally, remove the amniotic membrane - the innermost extraembryonic membrane consisting of a fluid-filled sac that surrounds and protects the embryo - to release the mouse embryo.

The recovered perinatal embryos can be used for studying early mammalian development.