James Watson, an American born Molecular Biologist along with Francis Crick a British molecular biologist, physicist, and neuroscientist are most noted for being the co-discoverers of the structure of the DNA molecule in 1953. Watson and Crick talked a great deal about DNA and the idea that it might be possible to make a guess as good molecular model of its structure
Another Scientist, Linus Pauling had published a model of the protein alpha helix in 1952. Using Pauling's expertise in crystallization, James Watson took this step further when he and Francis Crick studied the DNA molecule with X-ray diffraction. Crick played a important role with the X-ray diffraction studies. He witnessed many of the mistakes that other Scientists were making while they were trying to determine a stable helix form. Because he studied the mistakes that Pauling and others made with the alpha helix, Crick and Watson were able to avoid the same kinds of mistakes when studying the structure of DNA.
One thing that Watson and Crick learned was the importance of the double bond integrity to the nucleic acids and proteins in the DNA structure. From their studies,they deduced the double helix structure of DNA and submitted their findings to Nature magazine in 1953.
Watson and Crick obtained a very valuable piece of experimentally-derived information from X-ray diffraction images. These images had been obtained by Maurice Wilkins, Rosalind Franklin, and their research student, Raymond Gosling. Wilkins later shared his findings with Watson and Crick Wilkins and another Scientist, Alexander Stokes had thought that DNA might have had a helical structure but fellow Scientist Rosalind Franklin thought that they were off base and that they should keep working. Because Pauling had been successful with the alpha helix, Waton and Crick( believing that they and Wilkins were correct) rushed to find the structure of DNA, falsely thinking that they had to compete with Linus Pauling for the discovery Their first attempt at the structure was incorrect.
Franklin had taken beautiful X-ray diffraction photos of the DNA molecule, but she didn't have the 3D molecular models that Watson and Crick had. Watson even used cardboard models of the bases known to be present in DNA to help him study the structure. Watson finally put all the pieces together. In the lab while studying the adenine, thymine, guanine and cytosine bases that make up DNA, he realized that the base pairs being held together by hydrogen bonds were all identical in shape. He realized that the pairs acted like rungs on a ladder in the twisting strands of DNA.
In 1962, Watson,Crick and Wilkins won the Nobel Prize in Physiology for their discoveries about nucleic acid in the structure of DNA. For all her work, Rosalind Franklin did not receive the award because she had died at the age of 37, and could not receive it posthumously.