Characterization of Oocyte Hardening Using a Microfluidic Aspiration-Assisted Electrical Impedance Spectroscopy System

This paper reports a microfluidic aspiration-assisted electrical impedance spectroscopy system (MAEIS) with the aim of characterizing oocyte hardening for in-vitro fertilization (IVF) purposes. A microfluidic-based cell trap device is utilized, which offers simple oocyte handling through hydrodynamic trapping. The aspiration of the zona pellucida (ZP), which is a gelatinous outer layer of extracellular matrix, at an orifice of the microfluidic channel was measured observer-independently by applying electrical impedance spectroscopy (EIS). Impedance spectra obtained from three different oocyte genotypes were fitted to an appropriate equivalent electrical circuit (EEC) model and correlated with the aspiration length changes via a novel analytical model. Therefore, Young’s moduli of the zona pellucidae were calculated and the different oocyte stages were successfully determined.