The Discovery of DNA - Samantha Simon, Dane Grunwell, Riley Smith

  • Friedrich Miescher

    Friedrich Miescher extracted DNA from the cell nuclei. He was unaware of it's function, but he knew it was not a protein. He also learned it was rich in nitrogen and phosphorus. Though he did not know much, this was the first step to many discoveries relating to DNA.
  • Frederick Griffith

    Frederick Griffith
    In hopes of creating a vaccine for pneumonia, Griffith tested mice with isolated harmless and harmful cells. Even when the harmful cells were killed, Griffith uncovered a clue about DNA. They transferred the message to kill the mice to the harmless cells when a mixture of the two was present.
  • Oswald Avery Maclyn McCarty & Colin McCleod

    They extracted S cells that contained only lipid, protein, and nucleic acid. it was treated with lipid and protein destroying enzyme and they found DNA.
  • Erwin Chargaff

    He said that the amounts of thymine and adenine are identical as are the amounts of cytosine and guanine. He also said that different species differ in its proportions of adenine and guanine.
  • Barbara McClintock

    Barbara McClintock
    Barbara McClintock is recognized for her discovery of jumping genes. While experimenting and studying maize, or corn, Barbara predicted the color of kernels based on alleles. She noticed in some cells a breakage in alleles causing streaks of color in some kernels that were meant to be colorless. These transposons (jumping genes) were Barbara's discovery.
  • Rosalind Franklin and Maurice Wilkins

    Rosalind Franklin specialized in x-ray crystallography. She managed to take then first clear x-ray image of DNA as it occurs in the cell. This famous image is known widely as photo 51, and was a piece of evidence used in later experiments by other scientists.
  • Alfred Hershey and Martha Chase

    Hershey and Chase discovered that DNA, in fact, was genetic material. During their experiments with bacteriophages, they learned that DNA transmits complete hereditary information.
  • Linus Pauling

    Linus Pauling
    Linus Pauling was always a fascinated chemist. In 1952, Linus Pauling incorrectly hypothesized a triple helix structure for DNA. From another researcher's seminar, Pauling observed an image from an electron microscope of very small biological structures; this was DNA. Pauling incorrectly sketched a triple stranded/helix model for this biological structure.
  • James Watson and Frances Crick

    James Watson and Frances Crick
    James Watson and Frances Crick disproved Linus' proposal of a triple helix. Linus originally thought the phosphate group formed the helical cord. With negatively charged phosphate groups repelling one another, a triple helix is impossible. James Watson and Frances Crick discovered this fact using an X-ray of the DNA structure, They're fame comes from the correct model of a double helix DNA structure.
  • Matthew Meselson & Franklin Stahl

    Said that the semi-conservative replication of DNA, such that each laughter molecule contains 1 daughter molecule
  • Paul Berg

    Paul Berg performed a gene splicing experiment in which he mixed together two spliced viruses. He mixed lambda, a bacterial virus, into the DNA of simian virus. His experiment resulted in the first man made recombinant DNA.
  • Frederick Sanger

    He resuarched the metabolism of amino acid lysine
  • Kary Mullis

    Kary Mullis discovered/created the polymerase chain reaction (PCR). PCR let chemists produce copies of specific pieces of DNA quickly.
  • J. Craig Venter

    J. Craig Venter
    The long, yet successful, project called the Human Genome began with J. Craig Venter. The Human Genome project was dedicated to mapping the location of genes in chromosomes. It began as early as 1988.