Photo on 1 25 19 at 10.25 am

The Discovery of DNA - Ryan Vance, Nathan Lifer

  • Friedrich Miescher

    Friedrich Miescher
    Born in 1844, Friedrich Miescher lived in Basel, Switzerland, He was the discoverer of nucleic acids. In 1869, Friedrich broke down molecules from pus to isolate the nucleic acids.
  • Frederick Griffith

    Frederick Griffith
    Frederick Griffith utilized two different strains of bacteria, one lethal to mice with the other not, to observe what he called the "transforming principle". He noticed that mice, when injected with either dead lethal cells or living non-lethal cells, were unharmed. In addition, he saw that mice would die when injected with both. Frederick Griffith concluded that some "transforming principle" had allowed the non-lethal cells to change. Interestingly, Frederick was British.
  • Barabara McClintock

    Barabara McClintock
    McClintock discovered that some genes do not stay in one place and instead can move around the chromosome. She called these genes transposons or jumping genes. She experimented with different types of corn kernels. She then took cells from each of them, dyed them, and observed them. She later posted her studies to the Cold Spring Harbor Symposium in which they stated it was to out there and hard to understand. McClintock later got a nobel prize for her experiment in 1983.
  • Oswald Avery, Maclyn McCarty, and Colin McCleod

    Oswald Avery, Maclyn McCarty, and Colin McCleod
    Oswald and his team continued Griffith's experiment by deactivating different potions of dead lethal bacteria. From this, they concluded that DNA was the hereditary material that made the non-lethal cells lethal. Oswald was American. This is interesting, because it shows that the research on DNA was global and not restricted to a single country.
  • Erwin Chargaff

    Erwin Chargaff
    Erwin separated DNA into different parts, and found that different species of animals and plants contained different amounts of A,C,G, and T. However, he concluded that the amount of A was consistently equal to T, and that the amount of C was always equivalent to G. He met James Watson and Frances Crick, but did not like them.
  • Alfred Hershey and Martha Chase

    Alfred Hershey and Martha Chase
    These researchers concluded that viruses used DNA to determine the characteristics of the new virus cells. Their experiment was conducted by making either a protein or DNA of a virus trackable with an isotope. Then, they allowed the viruses to use bacteria cells to reproduce. Alfred and Martha found that only the DNA marked viruses were radioactive. Martha Chase lived past the year 2003.
  • Linus Pauling

    Linus Pauling
    Linus was an extremely successful scientist. Using his expertise in x-ray crystallography and chemistry, he published a plethora of research. Linus spent time attempting to predict the correct model of DNA, but his triple-helix model was proven wrong. He was awarded a Nobel prize for his work in chemistry in 1954.
  • Rosalind Franklin and Maurice Wilkins

    Rosalind Franklin and Maurice Wilkins
    Rosalind Franklin and Maurice Wilkins used crystallography to observe, using two different strands of DNA with one being more hydrated than the other, that phosphates groups were on the exterior of a helix structure. Born in 1920, she died in 1958 and was not included in her partner's, Maurice Wilkins, Nobel Prize in 1962.
  • James Watson & Frances Crick

    James Watson & Frances Crick
    Watson and Crick discovered that the structure of DNA was that of a double helix. Using knowledge compiled by Alexander Todd, Erwin Chargaff, and Jerry Donohue alongside the high resolution x-rays given to them by Maurice Wilkins and Rosalind Franklin they built a model that not only agreed with Chargaffs rules but also wound around an axis.
  • Mathew Meselson & Franklin Stahl

    Mathew Meselson & Franklin Stahl
    Meselson and Stahl concluded that Watson and cricks model of DNA is semi-conservative. Semi-conservative means that each piece of DNA acts as a template to create a new piece. During the experiment Meselson and Stahl used the E-Coli bacteria as a model. They put the E-Coli strand in a isotope of nitrogen and watched. After a long time of taking some out they weighed it and found out it was semi-conservative.
  • Frederick Sanger

    Frederick Sanger
    Sanger recieved two nobel prizes for both of the projects he was apart of. The first was for him discovering the insulin molecule in which he used a chemical reagent to mark the N terminal amino group at the end of a polypeptide chain. While his second was in 1980 from his collaboration with Paul Berg and Walter Gilbert to base sequences in nucleic acids.
  • Paul Berg

    Paul Berg
    Paule Berg recieved a noble prize along with Walter Gilbert and Frederick Sanger for his research into recombinant DNA. Berg developed a few methods to split DNA molecules in certain places while attaching a piece of the DNA to a virus or plasmid.
  • Kary Mullis

    Kary Mullis
    Mullis created a way that was much easier to pull off that allows people to copy a specific sequence of DNA. This method is called PCR (Polymerase Chain Reaction). All you need in terms of ingredients are double stranded DNA that you want to copy, two short segments of single stranded DNA, nucleotides, and one polymerase enzyme. Then you just have to heat up all of the materials.
  • Craig Venter

    Craig Venter
    Venter was the first person to lead the first rough copy of the human genome sequence.