UC Berkeley

Recording the electrical signals of biological cells is key to understanding processes that are integral to life. Electrochromic optical recording (ECORE) utilizes the electrochromism of certain materials to noninvasively record bioelectric signals. In this dissertation, we study the development of microscope ECORE, an advanced method based on ECORE and a high-NA microscope objective. We demonstrate a twofold enhancement in the spatial resolution, while also achieving a detection limit — the smallest possible potential that can be detected — of 3 µV, an improvement on previous ECORE methods. We use microscope ECORE to record spontaneous extracellular action potentials from cardiomyocytes with single-cell resolution and simultaneously utilize the objective to image the cells, which was not possible with previous iterations of ECORE. Because microscope ECORE makes use of an objective and a commercial microscope base, it is also simpler to set up and easier to align than any previous ECORE setup. This makes it a more viable recording method for many labs and therefore makes ECORE more accessible to the broader research community, providing a powerful, noninvasive, label-free method to record vital bioelectric signals.