To understand the structure of DNA, Rosalind Franklin produced a kind of one-dimensional crystal aligning long fibres of DNA molecules. With this bundle-shaped crystal she obtained X-ray diffraction patterns of exceptional quality. When they saw these photographs, Watson & Crick (1953) deduced the structure of the double helix of DNA. Currently, the structures of very large biological macromolecules can be solved. For example, together with Venkatraman Ramakrishnan and Thomas Steitz, Ada Yonath has determined the structure of large ribosomes which are responsible for the production of all proteins in the living cells of humans, plants and bacteria; they were honoured by the Nobel Prize in 2009. Many others researchers have been awarded the Nobel price for their scientific achievements involving the use of crystallography (https://www.iucr.org/people/nobel-prize). Source: Voyage dans le cristal, adapted from IUCr Journals.