anti-H2AX Phospho-Ser 139 (1H2), mAb

Histones are proteins that package DNA into nucleosomes. Histones are responsible for maintaining the shape and structure of a nucleosome. One chromatin molecule is composed of at least one of each core histones per 100 base pairs of DNA. There are five families of histones known to date; these histones are termed H1/H5, H2A, H2B, H3, and H4. H2A is considered a core histone, along with H2B, H3 and H4. Core formation first occurs through the interaction of two H2A molecules. Then, H2A forms a dimer with H2B; the core molecule is complete when H3-H4 also attaches to form a tetramer. Histone H2A is composed of non-allelic variants, including H2A.1, H2A.2, H2A.X, and H2A.Z. H2A packages DNA molecules into chromatin and has been correlated with DNA modification and epigenetics. H2A plays a major role in determining the overall structure of chromatin and regulates gene expression. Protein modification on histone H2A exist and can sometimes result in a change in function. Different H2A variants were exploited to have different functions, genetic sequences and modifications. DNA double strand break (DSB) are leading to the early phosphorylation of Histone H2AX. Phosphorylated Gamma-H2AX is the first step in the recruitment of the DNA repair protein at the foci site. They are consequently very good biomarkers of DNA double strand break as well as check point for cell cycle arrest following DSB. Measuring gamma-H2AX phosphorylation has become a gold standard in DNA damage and repair for DSB events.