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Miescher
Friedrich Miescher discovered nuclein in the nuclei of human white blood cells, known as deoxyribonucleic acid (DNA). He planned to isolate and characterize the protein components of white blood cells. To do this, he made arrangements for a local surgical clinic to send him pus-saturated bandages, which he planned to wash out before filtering the white blood cells and extracting their various proteins. -
Chargaff
Chargaff discovered that no matter where DNA come from, the number of adenine bases always equaled the number of thymine bases and the number of guanine bases always equaled the number of cytosine bases. This meant that there are equal amounts of purine bases and pyrimidine bases. These rules became known as Chargaff's Rules. He later discovered another rule which was that the composition of DNA varied from one species to another in the amounts of bases A,G,T, and C. -
Franklin
Franklin used x-ray diffraction which helped her make a crucial contribution to the structure of DNA. She used these x-ray machines to get a clear or unvague image of the DNA. Franklin introduced x-rays into science which helped viewing DNA possible and easy. -
Hershey and Chase
Hershey and Chase's experiment showed that DNA is the genetic material of the virus called T2 that infects the bacterium E.coli. They suspected that replication was too complicated a process for a molecule basic like DNA. Through this experiment, it was proved that proteins weren’t the genetic material but it was DNA. -
Watson and Crick
Watson and Crick discovered that the structure of DNA was a double-helix polymer, or a spiral of two DNA strands,each containing a long chain of monomer nucleotides, wound around each other. They also discovered genetics and that it is passed from generation to generation. Watson and Crick used X-ray data and model building to find the information they know about DNA. -
Meselson and Stahl
The Meselson-Stahl experiment by Matthew Meselson and Franklin Stahl showed that DNA replication was semiconservative.
Semiconservative replication means that the DNA double helix strand, on replication, produces two double-stranded DNA helices. Each one has an original DNA helix strand and one new synthesized DNA helix strand. He contributed from Watson and Crick discovery of the double-helix structure. -
Works Cited
"The History of DNA Timeline." DNA Worldwide. N.p., 30 Sept. 2015. Web. 23 Jan. 2017. https://www.dna-worldwide.com/resource/160/history-dna-timeline.
"Erwin Chargaff." DNAbioB - Erwin Chargaff. N.p., n.d. Web. 23 Jan. 2017. http://dnabiob.wikispaces.com/Erwin+Chargaff.
