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Frederick Griffith
He was a British bacteriologist, and creator of the Griffith's Experiment. Griffith injected heat killed smooth pneumococci and live rough pneumococci into mice, killing them. However, he observed that many of the rough pneumococci transformed into the smooth ones. -
Avery, MacLeod, and McCarty
Three scientist who conducted an experiment to prove bacterial transformation, caused by DNA. Everyone knows that our body produces antibodies to fight off diseases, and this is what they were trying to discover. Two strains of DNA were used- a harmful and a harmless strain. The harmful strain had been deactivated, but still passed characteristics of being harmful onto the harmless strain, changing it. -
Erwin Chargaff
Erwin Chargaff was an Austrian biochemist who discovered two rules that led to and confirmed the double-helix structure theory of DNA. The first rule stated that the number of guanine units equals the number of cytosine units and the number of adenine units equals the number of thymine units (G=C, A=T). His second rule said that the composition of DNA varies from one species to another. -
Hershey and Chase
Hershey and Chase designed a series of experiments to test the presence of DNA. To start, they added radioactive phosphorous-32 into a phage to isolate the DNA. After adding the radioactive elements, the bacteria infected the bacteriophage, the DNA from the infected inserted itself into the other. Since the DNA was marked, Hershey and Chase were able to observe the process. -
Rosalind Franklin
A British biophysicist and an x-ray crystallographer, her research and experiments gave better understandings of DNA to the scientific community. Her work and research papers show that she determind the location of the phosphate group in the DNA molecule, and discovered the B-form helix. She is most famous for her photograph, nicknamed "Photo 51", showing the x-ray diffraction of DNA. -
James Watson and Francis Crick
James Watson and Francis Crick, two scientist (whose experiments would later win them nobel prizes), conducted an experiment to determine the structure of DNA. After attending several lectures, they proposed that DNA was made in a double helix shape, one going up and the other going down. They constructed a model of the DNA and added to it over time.
