Anti-H2B clustered histone 1 antibodies are used for the immunodetection of the protein encoded by the H2BC1 gene. In humans, the canonical protein has a reported length of 127 amino acid residues and a mass of 14.2 kDa. Its subcellular localization is in the nucleus. It is reported to be mainly expressed in the testis, and the corresponding protein is also present in mature sperm. It is a member of the Histone H2B protein family. Post-translational modifications have been described, including methylation, ubiquitination, acetylation and phosphorylation. Other names for this target antigen include H2B histone family, member U, (testis-specific), histone 1, H2ba, histone H2B, testis, histone cluster 1 H2B family member a, histone cluster 1, H2ba, and histone H2B type 1-A. Gene orthologs have been identified in the mouse, rat and chimpanzee species.