Oocyte Treatment and Preparation for Microinjection

Non-contact ultrasound oocyte denudation

“…Oocyte denudation is a crucial prerequisite for unequivocal evaluation of oocyte maturity and successful intracytoplasmic sperm injection. 1,2 Residual cumulus cells can potentially prevent the oocyte from being adequately manipulated and may represent a source of DNA contamination during trophectoderm biopsy for PCR-based preimplantation genetic testings. 3,4 The established manual denuding method, developed decades ago, consists of two steps: the enzymatic digestion and then the mechanical stripping of the cumulus using pipettes.…”

“…9,10 Finally, it has been found that the entire denudation procedure is highly skill dependent, time sensitive and frequently suffers from intra operator variability. 2,11…”

“…By gently shaking and squeezing the cells, it eliminates the potential damage that can be incurred using the current methods for COC denudation such as zona pellucida fracture, MS dislocation, PVS expansion, or oocyte activation. 2 The IDTs that produce the ultrasound waves are either embedded inside or circumscribed on the periphery of the microwells similar to those commonly used by embryologists for embryo development. Using grating reflectors in one direction, and a slight difference in the resonance frequency in the other, we are able to switch the acoustofluidic field direction by slightly altering the actuation frequency without using multiple signal ports.…”