Mouse embryos cultured in amniotic fluid

One thousand mouse embryos were collected over a period of 6 weeks and randomly assigned to either amniotic fluid aspirated during routine amniocentesis from normal 16 weeks pregnant patients or Earle's medium. The embryos were cultured for 72 hours at 37 degrees C in 5% carbon dioxide in air. Osmolarity, pH, partial arterial carbon dioxide pressure and HCO3- were checked before culture and again at the end of culture. Embryos were assessed according to the stage of development, namely degenerate embryos, morulae and blastocysts. The blastocysts were further divided according to their stage of development. There was a significant improvement in blastulation rate to fully expanded blastocysts in the embryos cultured in the amniotic fluid. The amniotic fluid was fairly variable in composition, pH and osmolarity, whereas the Earle's medium was very uniform in composition between trials. It was concluded that amniotic fluid drawn at 16 weeks from normal women is a good culture medium for mice embryos.