Anti-UPP1 antibodies are used in the immunodetection of the protein uridine phosphorylase 1. In humans, the canonical protein has a reported length of 310 amino acid residues and a mass of 33.9 kDa. Up to 2 different isoforms have been reported for this protein. It is notably expressed in the small intestine, oral mucosa, esophagus, duodenum, and appendix. A member of the PNP/UDP phosphorylase protein family, Upp1 is known to catalyze the reversible phosphorylytic cleavage of uridine and deoxyuridine to uracil and ribose- or deoxyribose-1-phosphate. Synonyms for this target antigen include UP, UPASE, UPP, UPase 1, urdPase 1, and UDRPASE. UPP1 gene orthologs have been reported in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species. A number of Upp1 antibodies have been mentioned in research publications and have associated citations. These antibodies are most commonly used in Western Blot experiments, among other applications.