Dabsyl-L-proline is the dabsyl derivative of L-proline, primarily used as an internal standard in biochemical research for the high-performance liquid chromatography (HPLC) analysis of amino acids derivatized with dabsyl chloride. It provides a reference peak for accurate detection and quantification, enhancing sensitivity and resolution in complex biological samples. Additionally, it supports peptide synthesis and proteomics studies by aiding in the identification and characterization of peptides and proteins. Its applications also include studies of enzyme kinetics and metabolic pathways involving amino acids.