Anti-CYB561 antibodies are used in the immunodetection of the protein cytochrome b561. In humans, the canonical protein has a reported length of 251 amino acid residues and a mass of 27.6 kDa. Its subcellular localization is in the cytoplasmic vesicles. Up to 2 different isoforms have been reported for this protein. It is reported to be expressed in many tissues, in particular the brain especially in the cortex and hippocampus. CYB561 is reported to be a transmembrane reductase that uses ascorbate as an electron donor in the cytoplasm and transfers electrons across membranes to reduce monodehydro-L-ascorbate radical in the lumen of secretory vesicles. Synonyms for this target antigen include FRRS2, ORTHYP2, transmembrane ascorbate-dependent reductase CYB561, cytochrome b561 family, member A1, ferric-chelate reductase 2, and CYB561A1. CYB561 gene orthologs have been reported in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species. These CYB561 antibodies are widely used in Western Blot experiments, among other applications.