Anti-COL9A3 antibodies are used in the immunodetection of the protein collagen type IX alpha 3 chain. In humans, the canonical protein has a reported length of 684 amino acid residues and a mass of 63.6 kDa. Its subcellular localization is in the extracellular matrix and is secreted. It is notably expressed in the skin, eye, and cartilage. A member of the Fibril-associated collagens with interrupted helices (FACIT) protein family, COL9A3 is reported to be a structural component of hyaline cartilage and vitreous of the eye. Post-translational modifications have been described, including glycosylation. The COL9A3 gene has been associated with the disease, Multiple epiphyseal dysplasia. Synonyms for this target antigen include EDM3, IDD, MED, STL6, collagen alpha-3(IX) chain, and DJ885L7.4.1. COL9A3 gene orthologs have been reported in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species. Immunohistochemistry is the most common application for the COL9A3 antibodies listed below. ELISA and Western Blot are also common applications.