Hydrindantin is primarily used in biochemical assays, particularly in the quantitative determination of amino acids. It plays a crucial role in the ninhydrin test, where it reacts with amino acids to produce a characteristic purple color, allowing for the detection and quantification of amino acids in various samples. This application is widely utilized in protein chemistry, food science, and clinical diagnostics to analyze protein content and amino acid composition. Additionally, hydrindantin is employed in research laboratories for studying peptide synthesis and degradation processes, aiding in the understanding of protein structures and functions. Its ability to form stable complexes with amino acids makes it a valuable reagent in analytical chemistry for accurate and sensitive measurements.