Arg-Arg beta-Naphthylamide Trihydrochloride is primarily used in biochemical research as a substrate for enzyme assays. It is particularly valuable in the study of proteolytic enzymes, such as trypsin and other serine proteases, due to its ability to release a fluorescent product upon enzymatic cleavage. This property makes it a useful tool for monitoring enzyme activity and kinetics in vitro. Additionally, it is employed in the development of diagnostic assays to detect and quantify protease activity in biological samples. Its application extends to pharmaceutical research, where it aids in screening and evaluating potential protease inhibitors as therapeutic agents. The compound’s fluorescent characteristics also make it suitable for use in high-throughput screening methods, enabling efficient and sensitive detection of enzymatic reactions.