The most important photograph ever taken?
This is Photo 51, taken in 1952 by Rosalind Franklin. The photograph is an X-Ray diffraction image of hydrated DNA, the result of a 60-hour exposure, and was the key to the development of the double-helix model of DNA. The discovery led to Watson, Crick, and Wilkins being awarded a Nobel Prize in 1962.
The image one of about a million resources related to genetics being put online by the Wellcome Trust.