The location of histone H5 on nucleosomes has been determined by binding anti-H5 antibodies to dinucleosomes, and recording the position of the bound IgG molecules using electron microscopy. Two types of antibody were employed, a total IgG fraction prepared from rabbits immunized with H5/RNA, which reacted to all three domains (NH2-terminal, central globular, and COOH-terminal) of H5, and an im...