Franklin's X-Ray Crystallography Experiments
Regular substances like crystals diffract X-rays in characteristic patterns according to their physical structure. The X-ray photograph at right shows the diffraction pattern of a crystallized DNA molecule. The cross pattern in the middle is characteristic of a helical molecule with regular repeats; the broad bands at top and bottom give an indication of the periodicity of the repeats.
(1920-1958), who made the photograph, worked as a post-doctoral
researcher in the lab of Maurice
and approached the structure of DNA as a physical problem in
structure. Opinion and evidence vary as to how she interpreted her
in the context of the biological problem of gene structure. Wilkins
showed the photograph
to Watson, who immediately realized its implications. Watson, Crick,
subsequently received the Nobel Prize in 1962 for solving the structure
of DNA. By the time of the award, Franklin was dead: the Nobel
not awarded posthumously, nor to more than three persons.
Watson's autobiographic account of the discovery of "The Double Helix" (1968) paints an
unflattering personal picture of Franklin, which was widely criticized
as inaccurate and sexist. Anne
Sayre's biography, "Rosalind Franklin
and DNA" (1975) discusses the challenges faced by women in
science. Watson and Crick repeatedly acknowledged that
they could not
have solved the structure without Franklin's evidence.