Thymidine 5′-monophosphate p-nitrophenyl ester sodium salt is primarily used in biochemical research as a substrate for enzymes such as phosphatases and nucleotidases. It helps in studying enzyme kinetics and mechanisms due to its ability to release p-nitrophenol upon hydrolysis, which can be easily detected spectrophotometrically. This compound is also valuable in diagnostic assays for measuring enzyme activity in biological samples. Additionally, it serves as a tool in molecular biology for investigating nucleotide metabolism and related pathways. Its application extends to drug development, where it aids in screening for enzyme inhibitors.