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
Rudolf Signer from the Thymus of calves, of which he took 15 grams of extraordinarily pure DNA to London. In England he gave it to various scientists, among them Maurice Wilkins, in order to promote research in the field. The analysis of X ray images of these DNA samples in Wilkins' laboratory allowed James Watson and Francis Crick to discover the double-helix structure of DNA. Rests of the DNA which Signer brought to England, survive today in the collection of King's College, London. Over 250 of Signer's scientific writings were published during his lifetime. The Lavoisier Medal was awarded to him for