Development of Oxygen Consumption Analysis with an on-Chip Electrochemical Device and Simulation.

The O2 consumption rate of embryos has been attracting much attention as a key indicator of cell metabolisms and development. In this study, we propose an on-chip device that enables the accurate, easy, and noninvasive measurement of O2 consumption rates of single embryos. Pt electrodes and micropits for embryo settlement were fabricated on Si chips via microfabrication techniques. The configuration of the device enables the detection of O2 concentration profiles surrounding the embryos by settling embryos into the pits with a mouth pipet. Moreover, as the detection is based on an electrochemical method, the influence of O2 consumption on the electrodes was also considered. By using a simulator (COMSOL Multiphysics), we estimated the O2 concentration profiles in the device with and without the effects of the electrodes. Based on the simulation results, we developed a normalization process to calculate the precise O2 consumption rate of the sample. Finally, using both the measurement system and the algorithm for the analysis, the respiratory activities of mouse embryos were successfully measured.