Used primarily as a biological stain in microscopy to highlight cellular components, particularly RNA, due to its strong affinity for nucleic acids. It is also employed in histology to differentiate between RNA and DNA in tissue samples. In addition, it serves as a fluorescent dye in flow cytometry and other fluorescence-based assays, aiding in the visualization and analysis of cellular structures. Its application extends to photodynamic therapy research, where it is studied for its potential in targeting and destroying cancer cells.