Primuline is widely used as a fluorescent dye in biological staining and microscopy. It is particularly effective in staining cellulose fibers, making it valuable in textile industries for quality control and fiber identification. In microbiology, Primuline is utilized to stain bacterial spores, aiding in their detection and study under fluorescence microscopy. Additionally, it is employed in histology to highlight specific tissue components, enhancing the visualization of cellular structures. Its fluorescent properties also make it useful in research applications, such as tracking cellular processes and studying protein interactions.