Anti-OPN antibodies enable researchers to detect and measure the OPN antigen in biological samples. This target is a reported synonym of the SPP1 gene, which encodes secreted phosphoprotein 1. This protein is known to function in cell adhesion and inflammatory response pathways, among other biological roles. The human version of OPN has a canonical amino acid length of 314 residues and a protein mass of 35.4 kilodaltons, although 4 isoforms have been identified. It is reported to be a secreted protein that is notably expressed in many tissues, such as the gallbladder and kidney. Other names for this target antigen include BNSP, BSPI, and ETA-1. Western Blot is a widely used application for the OPN antibodies listed below. In addition, ELISA is also a common application.