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Friedrich Miescher
Friedrich Miescher was not enthusiastic about this topic, but is known for isolating nuclein, from cell nuclei. He was the first to discover DNA as a molecule, and experimented with white blood cells. His work was very critical for learning more about DNA. One thing I found interesting was that he also determined that the nuclei was made up of hydrogen, oxygen, nitrogen, and phosphorus. -
Frederick Griffith
Frederick Griffith went to the University of Liverpool. He injected live S, live R, heat-killed S, and heat-killed S + live R into the mice. Griffith’s experiment with bacteria revealed the transforming principle, which led to the discovery that DNA acts as the carrier of genetic information. One thing I found that was interesting was that the R strain inherited some 'transforming principle' from the heat-killed S strain bacteria. -
Oswald Avery, Maclyn McCarty & Colin McCleod
Their experiment showed that DNA can transform the properties of cells, which explains genes. They also identified DNA as the transforming principle while studying bacteria that can cause pneumonia. They made an extract from the heat killed bacteria and treated it with enzymes that destroy lipids, proteins, and carbohydrates. They used the enzymes trypsin, chymotrypsin, ribonuclease, and deoxyribonucleic depolymerase. -
Barbara McClintock
She discovered that some genes could be mobile. McClintock studied chromosome breakage in corn which led her to a chromosome-breaking locus that could change its position in a chromosome. An interesting detail is that what he studied in that time period was extremely advanced. -
Erwin Chargaff
Erwin Chargaff found that DNA is made of four nitrogen bases, through. He adapted the paper chromatography technique that separated the four nitrogenous bases of DNA. His findings led to the discovery of the double helix. One interesting detail is that he created the Chargaff's rules. -
Alfred Hershey & Martha Chase
From their experiment they concluded that protein was not genetic material, and that DNA was genetic material. They used protein coats of phages and DNA of phages that were radioactively labeled. The phages infected bacteria with genetic material. This ended scientists' suspicions that genes were made of protein instead of DNA. -
Rosalind Franklin & Maurice Wilkins
They discovered the density of DNA and that it was hectical. They found this by using X-ray crystallography. Their findings led to the creation of the double helix. They took photo 51, and her work was shared to others unknowingly by Wilkins. -
James Watson & Frances Crick
They discovered the double helix structure of DNA. They also realized DNA is made up of two chains of nucleotide pairs that encode the genetic information. They used much of Franklins work with her not knowing. -
Frederick Sanger
Sanger proved that proteins were ordered molecules, and found the structure of mainly the B chain of Insulin. He also developed rapid DNA sequencing techniques. His experiment used partition chromatography, ion-exchange chromatography, and 2D paper chromatography. He was awarded the Nobel Prize for Chemistry in 1958. -
Matthew Meselson & Franklin Stahl
They invented the technique of a density gradient centrifugation and used it to prove DNA is replicated invented the technique of density gradient centrifugation and used this to prove that DNA is replicated semi-conservatively. They performed experiments on E. coli. The technique used centrifugal force to separate molecules based on their densities. -
Linus Pauling
Pauling was the greatest chemist of the twentieth century. He discovered the alpha-helix structure of proteins, and that sickle-cell anemia is a molecular disease. He made it possible for people to figure out the DNA code of organisms and develop techniques to help prevent the inheritance of genetic disorders. -
Paul Berg
Paul Berg created the first DNA molecule made of parts from different organisms. He inserted DNA from a bacterium into the virus' DNA. Berg was also the son of immigrants -
Kary Mullis
Mullis invented a process called polymerase chain reaction, in which a small amount of DNA can be copied in large quantities over a short period of time. He also won the 1993 Nobel Prize in Chemistry. -
J. Craig Venter
He is known for being the leader of the first draft sequence of the human genome, and put together the first team to transfect a cell with a synthetic chromosome. He created expressed sequence tags to speed up the human genome project.
