Used in density gradient centrifugation to separate biological molecules like DNA and viruses based on buoyant density. Commonly employed in molecular biology and biochemistry research. Also utilized in medical applications for diagnostic imaging and cancer treatment, particularly in radiation therapy. Serves as a source of caesium ions in chemical synthesis and in the preparation of other cesium compounds. Occasionally used in photoelectric cells and scintillation counters due to its electrical conductivity and response to radiation.