-
Friedrich Miescher
Miescher was the first to identify DNA as a distinct molecule. When he was working, he discovered a substance containing phosphorous and nitrogen in the nuclei of white blood cells found in pus. At first, he named the substance nuclein because it appeared to come from cell nuclei. It later became known as nucleic acid, and is now known as DNA. -
Frederick Griffith
In 1928, Frederick Griffith studied two strains of bacterium. He was trying to create a vaccine to prevent pneumonia. Griffith then injected mice with this bacterium and found a cure for it. He discovered that there is some chemical "transferring principle" had transferred from the dead virulent into the alive bacteria remained free of infection. The model in his experiment were mice. Griffith was born in Hale, England and attended Liverpool University. He then worked at the Liverpool Infirmary. -
Barbra McClintock
Discovered that genetic information is not stationary when she was experimenting with the coloration of corn kernels. She traced the pigmentation changes in corn and observed them with a microscope. She discovered that those genes controlled the genes responsible for pigmentation. She also realized that the genes could move a chromosome to a different site, and affect the behavior of nearby genes. -
Oswald Avery, Maclyn McCarty, Colin McClead
The three determined that DNA causes bacterial transformation. In 1932, a British microbiologist named Frederick Griffith was working with two strains of a substance called "S. pneumoniae." One strand was encircled by virulent, and Griffith observed that that one could transform. In 1944, the three men determined that the transforming substance in the cell was DNA. -
Linus Pauling
Discovered that DNA was shaped in a helix, which paved the way for the discovery of DNA's double helix structure later on. One day, while he was recovering from a cold in his bed, he constructed a paper model of a polypeptide chain. He observed the helix shape it created, and named it the alpha helix. -
Erwin Chargaff
In 1944, Erwin Chargaff dropped everything to study DNA. Chargaff believed that living organism's differed because of their DNA. Chargaff then took DNA from different species and observed how they differed. He made something called the "Chargaff Rules" where DNA has a ratio. (A=T, C=G) The model for this experiment was DNA. Erwin lived in Vienna for the majority. He learned fluent Greek and Latin there. Later on he then became obsessed with chemistry and physics. -
Rosalind Franklin
Found the shape of the double helix. Franklin took x-ray diffraction photos of DNA. She observed that the DNA formed a double helix shape. -
Alfred Hershey and Martha Chase
In 1952, Alfred Hershey and Martha Chase conducted many experiments to try and prove that DNA was the genetic material, not protein. They injected bacteria (each separately) with proteins and DNA. The protein did not infect the bacteria while the DNA did. They demonstrated that DNA, not protein, is the genetic material in cells. The model of the experiment was the bacteria. Later on Alfred won the Nobel Prize for Physiology. Martha met Alfred when she was his assistant in his laboratory. -
James Watson and Frances Crick
James Watson and Frances Crick wanted to figure out the structure of DNA. After many fails, they found out the configuration of the four elements. Then they shifted their mo2del to resemble the ratio, A=T and C=G. They then discovered the double helix. The model of the experiment was a cardboard model that they used. James got his PhD from Indiana University. Frances graduated from University college of London. -
Matthew Meselson and Franklin Stahl
Meselson and Stahl got inspired by the Watson-Crick experiment. So they started experimenting on their own. They grew nitrogenous bacteria, to see it's growth under different lighting. They demonstrated that DNA replication is semi-conservatively. The model of the experiment was nitrogenous bacteria. Meselson later then was elected to the American Academy of Arts. Franklin went on to write his own book, "The Mechanics of Inheritance". -
Paul Berg
Paul Berg isolated genes and into mammalian cells. Then he studied the cells and discovered that their protein products expressed and even manufactured in quantity. The model of this experiment was the mammalian cells. Berg grew up in Brooklyn, New York. He went to Penn State and got a PhD in Biochemistry. -
Frederick Sanger
Developed the "plus and minus" method for DNA sequencing. This method generated a series of DNA molecules of varying lengths that could be seperated. In 1977, Sanger and his team used his system to sequence the first complete genome. -
Kary Mullis
Mullis invented the polymerase chain reaction (PCR.) The PCR is a technique that allows a specific section of DNA to be copied extremely fast. PCR uses the double-stranded DNA that will be copied, two Oligonucleotide primers, nucleotides, and an enzyme that copies DNA by joining free nucleotides. Once it is heated, the DNA is separated. The mixture is cooled, allowing the primers to attach themselves to the end sites on the strands of DNA. -
Kary Mullis Continued
The polymerase is able to begin copying the strands of DNA by adding nucleotides on the end of the strands. The process can then be repeated. -
J. Craig Venter
Craig Venter created the world's first synthetic life form in a landmark experiment. He identified the entire gene sequence corresponding to the adrenaline receptor. The model for his experiment were the adrenaline receptors. Craig Venter went to Boot Camp, was with the Navy, and served in Vietnam.
