The first part of the follicular fluid is clear, yellowish and voluminous, the middle part is slightly mixed and light red, and the last part is a small amount of bloody fluid. The follicular fluid was poured into a pre-warmed Petri dish and the egg-crown-thalmus complex (OCCCs) was searched for under the microscope. The egg and its surrounding complex floated in the follicular fluid like a jellyfish.
Chao Lan, Fertility Treatment Center, Qilu Hospital, Shandong University
Maturity of eggs (GV-MI-MII): During IVF we want to get mature eggs like the one shown on the right, only MII stage eggs can be fertilized properly.
MII: Mature egg, right, the structure of the nucleus has disappeared and the first polar body has been expelled, at this point, the structure of the nucleus is not visible in the cytoplasm and the first polar body is visible in the perivitelline space.
MI: immature egg, middle panel, the structure of the nucleus has disappeared, but the first polar body has not yet been expelled.
GV: immature egg, left panel, the structure of the nucleus has not yet disappeared, and the rounded nuclear structures can be seen in the cytoplasm of the egg at this stage.