Used in biomedical research to quantify levels of purine nucleoside phosphorylase (PNP) in human biological samples such as serum, plasma, or cell lysates. This ELISA kit enables researchers to study PNP activity in immune regulation, as elevated or reduced levels are associated with immunodeficiency disorders, autoimmune diseases, and certain cancers. It is commonly applied in clinical laboratories and pharmaceutical research to monitor disease progression, evaluate therapeutic responses, and support the development of targeted treatments involving purine metabolism. The assay provides high specificity and sensitivity for reliable detection of PNP protein concentrations in research settings.