Chemical. CAS 137993-41-0. Formula C26H26ClN3O5. MW 495.95. Rhodamine 800 is a near-infrared fluorescent dye, which was originally developed as a laser dye. Rhodamine 800 belongs to the rhodamine family and is one of the few rhodamines that have near infrared fluorescence. It displays bright red-orange fluorescence, making it an ideal choice for labeling proteins, nucleic acids, and other molecules in biochemical studies. Rhodamine 800 finds widespread use in research and analytical applications. It is used for detecting proteins in cells, tracking molecule movement and studying molecular interactions. In fluorescence microscopy and imaging, Rhodamine 800 enables visualization of organelles and molecules within living cells. It proves valuable in flow cytometry for measuring DNA levels and quantifying proteins and other molecules.