Disialylnonasaccharide-beta-pNP is primarily used in biochemical research as a substrate to study the activity of enzymes like sialidases and glycosidases. These enzymes are involved in the cleavage of sialic acid residues from glycoproteins and glycolipids, which is crucial for understanding cellular processes, pathogen-host interactions, and the development of therapeutic agents. The compound is also employed in the development of assays to detect and measure enzyme activity, aiding in the identification of enzyme inhibitors or activators. Additionally, it serves as a tool in glycobiology to investigate the structure and function of complex carbohydrates in biological systems.