Life their DNA inside the cell nucleus and some of their DNA in organelles, such as mitochondria or chloroplasts. In contrast, prokaryotes (bacteria and archaea) store their DNA only in the cytoplasm. Within the 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 identified by James Watson and Francis Crick in 1953, whose model-building efforts were guided by X-ray diffraction data acquired by Rosalind Franklin. Life is
James Watson his phage and other experimental research conducted at Indiana University, Statens Serum Institut (Denmark), CSHL, and the California Institute of Technology, Watson now had the desire to learn to perform X-ray diffraction experiments so he could work to determine the structure of DNA. That summer, Luria met John Kendrew, and he arranged for a new postdoctoral research project for Watson in England. In 1951 Watson visited the Stazione Zoologica 'Anton Dohrn' in Naples. In mid-March 1953, Watson and Crick deduced the double helix structure of DNA. Crucial to their discovery were the experimental data collected at Kings College — mainly