Calcium ionophore III is primarily used in research settings to study calcium signaling pathways within cells. It facilitates the transport of calcium ions across cell membranes, allowing scientists to manipulate intracellular calcium levels. This is particularly useful in understanding the role of calcium in cellular processes such as muscle contraction, neurotransmitter release, and cell proliferation. Additionally, it is employed in experiments involving calcium-dependent enzyme activation and apoptosis studies. Its ability to modulate calcium flux makes it a valuable tool in pharmacology and toxicology research to assess the impact of calcium on cellular function and response to various stimuli.