Photo 51 x ray diffraction image

History of DNA

  • Friedrich Miescher

    Friedrich Miescher
    Miescher had isolated various phosphate-rich chemicals, which he called nuclein (now nucleic acids), from the nuclei of white blood cells, paving the way for the identification of DNA as the carrier of inheritance.
  • Albrecht Kossel

    Albrecht Kossel
    He discovered nucleic acids. He contributed to the deciphering of the chemistry of nucleic acids and proteins, discovering nucleic acids, the bases in the DNA molecule, which constitute the genetic substance of the cell.
  • Phoebus Levene

    Phoebus Levene
    He studied the structure and function of nucleic acids. He characterized the different forms of nucleic acids, DNA from RNA, and found that DNA contained adenine, guanine, thymine, cytosine, deoxyribose, and a phosphate group.
  • Frederick Griffith

    Frederick Griffith
    He performed the experiment known as the "Griffith experiment", discovered what he called the "transformation principle", the transmission of genetic information from one bacterium to another, but at the time it was not known whether this related to DNA or proteins.
  • Oswald Avery

    Oswald Avery
    Together with his collaborator Maclyn McCarty, he discovered that DNA (deoxyribonucleic acid) is the material from which genes and chromosomes are made and how they define human sexuality. Previously it was believed that proteins were the carriers of genes.
  • Erwin Chargaff

    Erwin Chargaff
    He discovered two rules that helped lead to the discovery of the DNA double helix. He analysed the nitrogenous bases of DNA in different forms of life, concluding that, the amount of purines is always in equal proportions to those of pyrimidines (contrary to what Phoebus Levene proposed), the proportion was equal in all cells of individuals of a given species, but varied from one species to another.
  • Martha Chase y Alfred Hershey

    Martha Chase y Alfred Hershey
    They conducted a series of experiments to confirm whether DNA is the basis of genetic material (and not proteins), in what was called the Hershey and Chase experiment. Hershey and Chase found that S-35 lies outside the cell, while P-32 was found inside, indicating that DNA was the physical carrier of hereditary material. S-35 and P-32 are radioactive isotopes.
  • Rosalind Franklin

    Rosalind Franklin
    Whose work was fundamental to the understanding of the molecular structures of DNA (deoxyribonucleic acid), RNA (ribonucleic acid), viruses, carbon and graphite. Although her work on carbon and viruses was recognized during her lifetime, her contribution to the discovery of the structure of DNA went unrecognized. She has been labelled an "aggrieved heroine", Rosalind Franklin was the first person to publicly suggest that the phosphate groups of DNA should be on the outside of the molecule.
  • Francis Crick and James Watson

    Francis Crick and James Watson
    They published the famous structure of the DNA double helix in a one-page article in the journal Nature. From it came the explanation for understanding how living things reproduce, how hereditary information is passed from parent to child, how this information can be changed by mutations and give rise to hereditary diseases, how it plays a role in biological evolution, and why all living things evolved from a common ancestor.