Anti-CATSPERD antibodies are used in the immunodetection of the protein cation channel sperm associated auxiliary subunit delta. In humans, the canonical protein has a reported length of 798 amino acid residues and a mass of 90.5 kDa. Its subcellular localization is in the cell projections. Up to 2 different isoforms have been reported for this protein. It is notably expressed in the testis. A member of the CATSPERD protein family, CATSPERD is reported to be an auxiliary component of the CatSper complex, a complex involved in sperm cell hyperactivation. Post-translational modifications have been described, including glycosylation. Synonyms for this target antigen include catSperdelta, cation channel sperm-associated protein subunit delta, catsper channel auxiliary subunit delta, transmembrane protein 146, and catSper-delta. CATSPERD gene orthologs have been reported in the mouse, rat, bovine and chimpanzee species. These CATSPERD antibodies are widely used in Western Blot experiments, among other applications.