H3 is a core component of the nucleosome, functioning in DNA compaction and availability to transcription machinery. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodelling. Similar to the other core histone, H3 has a globular domain and a flexible N-terminal domain, “histone tail” which can undergo modifications such as acetylation, methylation, phosphorylation and ubiquitination. There is a wealth of data recording these modifications but understanding their significance is not as clear. H3K23me3, an enriched modification in heterochromatin, is known to bind histone demethylase KDM4A. H3K23me3 is also necessary for timely and accurate meiotic divisions.

H3 amino acids 14-34 with lysine 23 trimethylated are provided here with a biotin label for easy use in detection by fluorescence microscopy, ELISA or western blots. Alternatively, it can be purified for protein-protein interactions with the appropriate affinity purification protocol.