Tetraethylammonium bromide is widely used in biochemical research as a potassium channel blocker. It helps in studying the function and regulation of potassium channels in various cells, which is crucial for understanding cellular communication and electrical signaling in the nervous system. Additionally, it is employed in electrophysiology experiments to isolate and analyze specific ion currents. In organic synthesis, it serves as a phase-transfer catalyst, facilitating reactions between compounds in different phases, thereby improving reaction efficiency and yield. Its applications also extend to the preparation of ionic liquids, which are used in green chemistry for their non-volatility and thermal stability.