Double Helix: How an Image Sparked the Discovery of the Secret of Life
helix structure in just a few hours by drawing on paper while sick in bed Franklin believed sketches or models could only come after meticulously collecting data She took careful measurements and made calculations based on her X-ray photographs of the DNA molecule Numbers and notes filled her notebooks not drawings Wilkins welcomed his friend Watson into his office He was glad for an opportunity to grumble about Franklin Though Wilkins and Franklin both studied DNA they competed rather than worked together The lab’s director John Randall had even given them separate workspaces and divided the DNA research so they could work independently Franklin enjoyed working alone but she also found King’s College old fashioned and unwelcoming Scientists gathered in a men-only commons room for lunch and discussion She wrote to a friend in Paris that at King’s there was nobody with whom I particularly want to discuss anything scientific or otherwise 3 Women including scientist Rosalind Franklin were not always welcomed to the male-dominated collegiate world Franklin refused to discuss anything scientific with Watson during his trip to the King’s labs Yet without knowing it she would help him and his Cambridge colleague Francis Crick make history Out of a drawer in his office Wilkins pulled an X-ray photograph made in the lab by Franklin and her assistant Raymond Gosling She had labeled it Photo 51 Without asking her permission and in a move that many scientists have said is unethical Wilkins showed it to Watson
Linus Pauling received a copy of Photo 51 taken by Rosalind Franklin The name of her graduate assistant Raymond Gosling also appears on the note To the untrained eye the photograph was simply a grainy black and white image of dark marks scattered in roughly the shape of an X But to someone skilled in crystallography the science of determining the arrangement of atoms in crystals it was a clear portrait of a DNA fiber taken with X-rays John Bernal an early developer of the X-ray photography technique praised Franklin for the extreme clarity and perfection in everything she undertook Her photographs are among the most beautiful X-ray photographs of any substance ever taken 4 Wilkins knew the importance of Franklin’s Photo 51 The X shape confirmed his guess of DNA’s structure I had this photograph and there was a helix right on the picture You couldn’t miss it 5 he later said Watson saw it too The instant I saw the picture my mouth fell open and my pulse started to race 6 he remembered While riding the train back to Cambridge Watson drew what he remembered of Photo 51 in the margin of a newspaper Helices curved around each other like spiral staircases He did not want to forget what he had seen before he could share it with his lab mate Francis Crick Unlike Wilkins and Franklin he and Crick were friendly and
shared ideas The simplicity of the image he had seen excited him When he got back to the lab he waited for Crick Francis did not get halfway through the door before I let loose that the answer to everything was in our hands 7 Watson said later But seeing the drawing based on Franklin’s superb photograph also worried Watson He supposed that if Pauling put one of his assistants to taking DNA photographs they might get one as clear as Photo 51 and in a week at most Linus would have then structure 8 Watson and Crick raced to be first in solving the mystery of DNA’s structure They had no time for data collection They would build a model in three dimensions Too impatient to wait for the lab machine shop to cut metal into model-making pieces to get started they used cardboard cutouts Francis Crick became a molecular biologist after first studying physics Franklin’s Photo 51 still left important questions unanswered It showed DNA was a helix but not how many chains twirled around each other like stripes on a candy stick It did not show whether the nitrogen bases fit inside the chains like ladder rungs or sprouted outward For several weeks the scientists arranged and rearranged the pieces in their lab ROSALIND FRANKLIN THE WOMAN BEHIND PHOTO 51 When 15-year-old Rosalind Franklin decided to become a scientist in the 1930s her father worried Most scientists at the time were men The British Royal Society which promotes scientific research was established in 1662 but did not admit a female scientist until 1945 Franklin studied chemistry at Cambridge University and went on to receive a PhD Cambridge really did for Rosalind everything that a good university should It gave her a profession a philosophy of life said her biographer Brenda Maddox She emerged a mature socially and politically aware individual and she was ready to become a working scientist 9 She soon won admiration for her early work in a Paris lab in the 1940s She
pioneered the use of X ray photography to study the structure of coal A colleague wrote I considered her a genius and I don’t use that word lightly 10 In 1951 she began work at King’s College in London using her X-ray techniques to study DNA James Watson and Francis Crick admitted in 1954 that their solution to the DNA structure would have been most unlikely if not impossible 11 without Franklin’s X-ray data Still they did not treat her as an equal I’m afraid we always used to adopt let’s say a patronizing attitude towards her 12 Crick later said After leaving King’s College Franklin became well known for her work on the structure of viruses including the polio virus Her work was cut short by her death from ovarian cancer in 1958 when she was just 37 years old Years of exposure to X-rays was likely the cause Her list of admirers has only grown in the decades since In his 1982 Nobel Prize acceptance speech Aaron Klug a friend and collaborator spoke of her inspiring example of tackling large and difficult problems 13 A plaque marks where she lived and worked in London And every year the British Royal Society presents the Rosalind Franklin Award to support women working in science technology engineering and math Rosalind Franklin On the morning of February 28 1953 Watson made a new arrangement of the pieces They fitted together in an elegant form that swooped in two spiral staircases curving around each other for 6 feet 1 8 meters Crick walked in and it was quite a moment Watson later remembered We felt sure that this was it Anything that simple that elegant just had to be right 14 Besides its beauty Crick also recognized the logic of the structure the two ladders could unzip to allow the DNA molecule to copy
