Anti-OPN3 antibodies are used in the immunodetection of the protein opsin 3. In humans, the canonical protein has a reported length of 402 amino acid residues and a mass of 44.9 kDa. Its subcellular localization is in the cell membrane and cytoplasm. Up to 2 different isoforms have been reported for this protein. It is reported to be expressed in tracheal airway smooth muscle. A member of the G-protein coupled receptor 1 protein family, OPN3 is known to be involved with GPCR signaling pathways and keratinocyte differentiation. Post-translational modifications have been described, including glycosylation. Synonyms for this target antigen include PPP1R116, encephalopsin, opsin 3 (encephalopsin, panopsin), protein phosphatase 1, regulatory subunit 116, and ECPN. OPN3 gene orthologs have been reported in the mouse, rat, bovine, zebrafish, chimpanzee and chicken species. A number of OPN3 antibodies have been mentioned in research publications and have associated citations. Western Blot is a widely used application for these antibodies. ELISA, Immunofluorescence, and Immunohistochemistry are also common applications.