DNA archaea) store their DNA only in the cytoplasm. Within eukaryotic chromosomes, chromatin proteins, such as histones, compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed. DNA was first isolated by Friedrich Miescher in 1869. Its molecular structure was first identified by James Watson and Francis Crick at the Cavendish Laboratory within the University of Cambridge in 1953, whose model-building efforts were guided by X-ray diffraction data acquired by Raymond Gosling, who was a post-graduate student of Rosalind Franklin. DNA is used by researchers as a
Maurice Wilkins the helical nature of the A-form. In early 1953 Watson visited King's College and Wilkins showed him a high quality image of the B-form X-ray diffraction pattern, now identified as photograph 51, that Franklin had produced in March 1952. With the knowledge that Pauling was working on DNA and had submitted a model of DNA for publication, Watson and Crick mounted one more concentrated effort to deduce the structure of DNA. Through Max Perutz, his thesis supervisor, Crick gained access to a progress report from King's College that included useful information from Franklin about the features of DNA she had