Anti-MED21 antibodies are used in the immunodetection of the protein mediator complex subunit 21. In humans, the canonical protein has a reported length of 144 amino acid residues and a mass of 15.6 kDa. Its subcellular localization is in the nucleus. A member of the Mediator complex subunit 21 protein family, MED21 is a known component of the Mediator complex, a coactivator involved in the regulated transcription of nearly all RNA polymerase II-dependent genes. Synonyms for this target antigen include SURB7, hSrb7, mediator of RNA polymerase II transcription subunit 21, RNA polymerase II holoenzyme component SRB7, RNAPII complex component SRB7, and SRB7. MED21 gene orthologs have been reported in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species. Some MED21 antibodies may have been used in research and have associated citations. Western Blot is a widely used application for these antibodies. ELISA and Immunofluorescence are also common applications.