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Friedrich Mischer
Mischer was a chemist who extracted and observed DNA for the first time. He concluded that it wasn't a protein but was rich in both nitrogen and phosphorous. This was ground-breaking because it was the first legitimate observation of DNA.
Interesting Fact: Mischer originally wanted to be a priest but his father rejected the idea so he became a doctor. -
Frederick Griffith
Griffith experimented with mice and the pneumonia virus to attempt to create a vaccination. He found that heat had destroyed a bacteria's ability to cause pneumonia but did not destroy the hereditary material. This discovery contributed to the better understanding DNA and the hereditary information it holds.
Interesting fact: Griffith attended Oxford University -
Barbara McClintock
McClintock researched the transposition in corn chromosomes. Her findings did not get much credit at the time because transposition was not known much of. Her research greatly contributed to the beginning of transposition findings.
Interesting fact: Barbara McClintock was awarded the Nobel Prize for physiology or medicine in 1983 -
Oswald Avery, Maclyn McCarty, and Colin McCleod
Avery, McCarty, and McCleod elaborated on Griffith's experiment and concluded that DNA was the transforming principle. They found this through conducting the same experiment as Griffith but each time removing a variable to detect which one causes the change. They found that DNA is hereditary material. This sparked further experiments finding out more about the hereditary information that DNA holds.
Interesting fact: Both Avery and McCarty won an Albert Lasker Award -
Erwin Chargaff
Chargaff found that the amount of thymine had a corresponding amount as adenine, same with cytosine and guanine. He additionally found that the amount of thymine and adenine differed from species to species. This was important because it offered an image to scientists about what the amounts of these bases would be like.
Interesting fact: Chargaff became a U.S. citizen in 1940 -
Rosalind Franklin and Maurice Wilkins
Franklin and Wilkins were working on finding DNA's structure using x-ray crystallography. Franklin obtained the first clear image of DNA and she even determined the size of it. This sparked a huge rush for scientists to find the structure before she would. This was a major breakthrough for the study of DNA as it was finally revealed to what its basic structure is like.
Interesting fact: By the age of fifteen, Rosalind knew she wanted to be a scientist. -
James Watson and Francis Crick
Watson and Crick were trying to determine the structure of DNA. They are credited as the two who identified the well-known double helix shape of DNA. But, their early models resulted in many attempts and it wasn't until they saw Rosalind Franklin's image of DNA that they got the double helix correct. This was a pivotal moment for the research of DNA as it finally revealed the structure, the final piece to the puzzle.
Interesting fact: Francis Crick won a Nobel Prize for physiology and medicine. -
Alfred Hershey and Martha Chase
Hershey and Chase proved that DNA, and not protein, transmit a full complement of hereditary information. This was found through the realization after infectious particles carry information that make new viruses into their hereditary material. These experiments stemmed from the previous information on the ratio of phosphorous and sulfur in proteins compared to DNA.
Interesting fact: Alfred Hershey won the Nobel Prize for Physiology or Medicine in 1969. -
Linus Pauling
During the race to accurately find the structure to DNA, Pauling created a triple helix model with its bases on the outsides. While it was an inaccurate portrayal of DNA, it helped to propel other scientists along their research paths to be the first to find DNA's structure.
Interesting fact: Pauling has published almost 1200 books and papers, the majority being about scientific concepts. -
Matthew Meselson and Franklin Stahl
Meselson and Stahl found experimental proof of semi-conservative DNA replication. This assisted to prove the finding's of Watson and Crick on replication. Which then helped the community of scientists looking into replication by giving them the needed information on how DNA is replicated. -
Paul Berg
Berg assembles the first molecules of DNA that has a combination of genes grin different organisms. This helped to further genetic engineering as well as recombinant-DNA technology.
Interesting fact: Berg won the Nobel Prize for chemistry in 1980 (with Walter Gilbert and Frederick Sanger) -
Frederick Sanger
Sanger developed a rapid way of DNA sequencing. He discovered this through his initial investigation of ways to sequence RNA which gave him the technique that he used for DNA sequencing. This was very important as it made the identifying of nucleic acid so much easier.
Interesting fact: Frederick Sanger won the Nobel Prize for chemistry twice (1958 & 1980) -
Kary Mullis
Mullis invented the polymerase chain reaction which produces many copies of a specific piece of DNA. This allowed the advancement of DNA replication and study.
Interesting fact: Mullis won the Nobel Prize in chemistry in 1993 -
J. Craig Venter
Venter started a race for the sequencing of the human genome. Through this, "expressed sequence tags" were created which assist in the distinguishing during DNA sequencing.
Interesting fact: Venter won the National medal of Science in 2008
