Anti-H2A.J histone antibodies are used for the immunodetection of the protein encoded by the H2AJ gene. In humans, the canonical protein has a reported length of 129 amino acid residues and a mass of 14 kDa. Its subcellular localization is in the nucleus and chromosomes. Alternative splicing is reported to yield 2 different isoforms for this protein. A member of the Histone H2A protein family, it is an important component of nucleosome. Post-translational modifications have been described, including ubiquitination, acetylation and phosphorylation. Other names for this target antigen include H2A histone family member J, buforin I, and histone H2A.J. Gene orthologs have been identified in the mouse, rat, bovine and chimpanzee species.