19.1 Introduction 19.2 The nucleosome is the subunit of all chromatin 19.3 DNA is coiled in arrays of nucleosomes 19.4 Nucleosomes have a common structure 19.5 DNA structure varies on the nucleosomal surface
Arthur Kornberg (1918- ) of the U.S. produced DNA in a test tube. F. Sanger (1918- ) of Britain developed sequencing procedure for proteins, and later for DNA