Coumarin 504T is primarily used as a fluorescent dye in various scientific and industrial applications. Its strong fluorescence properties make it valuable in biological imaging, where it helps in tracking and visualizing cellular processes under a microscope. It is also employed in laser technology, particularly in dye lasers, where it serves as a gain medium to produce specific wavelengths of light. Additionally, Coumarin 504T finds use in analytical chemistry as a fluorescent marker for detecting and quantifying substances in complex mixtures. Its ability to emit bright, distinct fluorescence under UV light makes it a reliable tool in research and diagnostic applications.