Histones are relatively small proteins that contain a high proportion of positively charged amino acids, e.g., arginine and lysine. This positive charge allows histones to bind tightly to the negatively charged DNA. There are five basic types of histone molecules called H1, H2A, H2B, H3, and H4. Histones are abundantly present in virtually all eukaryotic cells. Human histone H2B is a 125 amino acid protein.WARNING This product is not for human or veterinary use.