Used as a fluorescent labeling reagent for primary amines in biochemical and analytical applications. It selectively reacts with amine groups to form stable thiourea derivatives, enabling detection and quantification of peptides, proteins, and amino-containing molecules via fluorescence spectroscopy. Its high sensitivity and favorable fluorescence properties make it suitable for high-performance liquid chromatography (HPLC) detection, cellular imaging, and studies requiring chiral recognition due to its stereochemistry. Commonly applied in research settings for probing biomolecular structure and interactions.