Photographic print of a DNA X-ray diffraction pattern known as Photograph 51 with annotations by Rosalind Franklin (1920-1958) and Aaron Klug (1926-2018). The original image was made by Franklin and her student Raymond Gosling (1926-2015) at King’s College London in 1952 and it was published in their 1953 Nature article “Molecular Configuration in Sodium Thymonucleate” alongside the article in which James Watson (1928-2025) and Francis Crick (1916-2004) proposed the double-helix structure of DNA. The photo contains three annotations on the reverse. An unsigned pen inscription reads “NaDNA ‘Structure B.’” Another pen inscription reads “Original print by Rosalind Franklin of the famous B form photograph. Labelled in her handwriting above. A. Klug 1968.” A pencil annotation reads “867.”