Used as a substrate in enzymatic assays to detect and measure the activity of α-galactosidase enzymes. It is particularly useful in biochemical research and diagnostic applications to study enzyme kinetics and identify enzyme deficiencies. The compound is also employed in microbiology for differentiating bacterial species based on their enzymatic profiles. Its hydrolysis by α-galactosidase releases 4-nitrophenol, which can be easily quantified spectrophotometrically, making it a valuable tool in high-throughput screening and laboratory experiments.