Time line

By KyleR16
  • Friedrich Miescher

    He was the first person to identify DNA as a distinct molecule at University of Tübingen. He did many experiments on the chemical composition of leukocytes which led to this discovery. A fact is he is perhaps best known for his incorrect tetranucleotide hypothesis of DNA.
  • Frederick Griffith

    He discovered that hereditary material moves between two strains of bacteria (R and S). He injected mice with this in different ways to prove that DNA can pass between them. He was the first to reveal the “transforming principle”. A fact is he died in 1941.
  • Oswald Avery, Maclyn McCarty & Colin McCleod

    They extracted lipid, protein, and nucleic acids from S cells to figure out which one transformed bacteria. They determined that DNA had to be the transforming principle. Most researches were shocked because they thought proteins were hereditary. Avery, MacLeod and McCarty identified DNA as the "transforming principle" while studying Streptococcus pneumoniae, bacteria that can cause pneumonia.
  • Alfred Hershey & Martha Chase

    They held experiments to figure out the composition of the hereditary material that bacteriophage inject into bacteria. These were done because they knew that proteins have more sulfur than phosphorus and DNA has more phosphorus than sulfur. They proved that what was injected was DNA not protein. A fact is he won the Nobel Prize.
  • Linus Pauling

    He figured out the helix shape of globular proteins which helped with more discoveries later in the DNA timeline. It also helped Watson and Crick with their discovery. A fact is Pauling is probably best known for working out the nature of the chemical bond
  • Erwin Chargaff

    He is mostly known for his rules he created. The most important is natural DNA, which is the number of guanine units is equal to the number of cytosine units and the number of adenine units is equal to the number of thymine units. A fact is that he died June 20, 2002
  • Barbara McClintock

    She discovered some genes could be mobile. She studied chromosome breakage which led to the discovery of chromosome-breaking locus. A fact is she won a Nobel Prize.
  • James Watson & Frances Crick

    They researched the structure of DNA. All the research before by people had led them to this point. Based on its known structures, they discovered the double helix. A fact is that they were awarded a nobel prize.
  • Rosalind Franklin & Maurice Wilkins

    They discovered the structure of DNA, physical, and chemical basis or how characteristics are passed down through generations using X-ray crystallography. This was the start of the research before Watson and Cricks big discovery. A fact about them is that they argued a lot and didn’t get along.
  • Frederick Sanger

    He discovered that proteins were ordered molecules. A fact is he won a Nobel Prize.
  • Matthew Meselson & Franklin Stahl

    They performed experiments to show that DNA replicated semi-conservatively. This proves that each strand of DNA is a template for synthesis of a new strand. A fact is that their experiment was because of a debate in the 1950s by other scientists.
  • Paul Berg

    He discovered how to insert DNA from a bacterium into a virus’ DNA. He created the first molecule made from parts of different organisms. This discovery is known as “hybrid DNA”. A fact is he won a Nobel Prize.
  • Kary Mullis

    She invented the process called polymerase chain reaction. This is where DNA can be copied into large quantities over a short period of time. She discovered this while working for Cetus Corporation in Emeryville, California. A fact is she died at the age of 74.
  • J. Craig Venter

    He is known for being the head of the first draft sequence of the human genome. He also made the first team to transfect a cell with a synthetic chromosome. A fact is that he founded a non profit organization.