Each month we will give a tip on how to improve your results, sourced either from the literature or our own research.
What should you look for in a cumulus-oocyte complex (COC) collection medium (OPU)?
ART Lab Solutions does not manufacture a cumulus-oocyte complex (COC) collection medium, as there are several suitable substitutes. In particular, media such as Vigro Complete Flush and EmCare plus an anticoagulant (heparin) are all perfectly suitable for OPU. What is not going to help your COCs to give the best results is using simple buffered media such as Dulbecco’s PBS, or even worse, straight unbuffered saline. We have a lot of data from both cow and mouse IVF that collection into energy substrate-free and unbuffered solutions can negatively impact oocyte quality within minutes. Indeed, when it was recommended to change to a more complete media to a commercial group who were collecting with saline supplemented with a little FCS some years ago, their embryo production rates instantly improved.
For those who work with abattoir-derived cattle COCs, the best collection media of all is the follicular fluid that you aspirate. Just keep your COCs in the aspirant until you’re ready to place into maturation media. The natural meiotic inhibitors found in follicular fluid will work to prevent rapid germinal vesicle breakdown in the oocyte, providing a more synchronous meiotic progression during IVM.
Unfortunately, working with other species such as sheep, requires media with anti-coagulants (heparin) for aspiration.
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