Used as a derivatizing agent in analytical chemistry, this compound is particularly effective for labeling amino acids, peptides, and proteins. It facilitates the detection and quantification of these biomolecules in various samples through techniques like HPLC and mass spectrometry. Its isothiocyanate group reacts with primary amines, forming stable thiourea derivatives, which are essential for accurate analysis in biochemical research and diagnostic applications. Additionally, it is employed in the study of protein structure and function, aiding in the identification of amino acid sequences and post-translational modifications. Its water solubility, due to the sulfophenyl group, enhances its utility in aqueous-based analytical procedures.