The discovery of DNA canít be applied to one specific date in history. In fact, itís a series of events and research activities that finally resulted in the discovery of DNA, itís structure and the way it functions.
The groundwork for the discovery of DNA can be traced back to the nineteenth century when a German biochemist made a breakthrough observation regarding the presence of nucleic acids. He found out the elements of sugar, phosphoric acid and nitrogenous bases in the nucleic acids. Studies after that concluded that sugar can be present in either of the forms of ribose and deoxyribose, hence the discovery of RNA and DNA.
Earlier it was thought that proteins carry the genetic material. However, in 1944, Oswald T Avery proved the case for DNA containing the genetic information. He was able to extract DNA from a specific kind of bacteria and transfer it to the cells of a bacterium of another kind. The latter showed heredity of certain traits that were present in the donor bacteria. Since only DNA was passed on in the process, Avery concluded that genes must consist of DNA.
Studies related to the discovery of DNA kept on being carried out by scientists and biologists across different universities, colleges and other research based institutes. Erwin Chargaff, a biochemist, made an important discovery in 1948. He found out a striking feature exhibited by the nitrogen bases in DNA; that their order and sequence changes but certain bases were always present in the same quantity.
The progress in the discovery of DNA then moved on to two premier educational institutes of the world, i.e. Cambridge University and Londonís King College. While James Watson and Francis Crick at Cambridge University were headed towards making physical models of DNA and eliminating the impossibilities in DNAís structure, Maurice Wilkins and Rosalind Franklin took the road of experimentation based on x-ray diffracted DNA images.
Unfortunately, the initial model proposed by Cambridgeís team failed but Watson came across some findings of Franklinís experiments leading towards the proposition for a helical structure of DNA. Franklin wasnít convinced of her findings yet but based on these findings, and adding the important discovery made by Chargaff. Watson and Crick conceptualized a double helix structure of DNA. Their model was so solid, matching with the results of experiments that the DNA research community had no option but to accept it and since then this great discovery of DNAís structure has opened many doors for advancement in DNA technology.