Porcine Cumulus Oocyte Complex Isolation: A Technique to Isolate Cumulus Oocyte Complex from Porcine Ovarian Follicle for In Vitro Fertilization

The porcine oocyte is surrounded by a compact multi-layered cluster of cumulus cells forming the cumulus-oocyte complex or COC. The innermost cumulus cells extend the processes through the zona pellucida of the oocyte. These processes develop both gap and intermediate junctions, which help in the intercellular transfer of molecules between the oocyte and surrounding cumulus cells. These bi-directional interactions maintain the viability of COCs which is a crucial determinant of successful in vitro fertilization or IVF.

To isolate COCs, submerge a few porcine ovarian follicles in a Petri dish containing the maturation media. This media contains hormones necessary for in-vitro oocyte maturation. Dissect ovarian follicles to release COCs and follicular fluid into the Petri dish. This fluid supplements the maturation media with additional nutrients and hormones essential for oocyte competence.

Aspirate the released follicular content and transfer it to another Petri dish. Visualize the plate under a microscope to identify undamaged COCs that exhibit normal morphology consisting of round oocytes with moderately granulated cytoplasm and an intact polar body surrounded by cumulus cells.

Isolate a single COC and transfer it to the maturation media-containing central well of an IVF plate. Store the plate at an optimum temperature until further use.