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Meischer
Mischer was the first one to have a simple idea of what DNA really was. Mishear discovered the nuclein in the nuclei of a white blood cell which today is know as DNA.Meischer had obtained the real purification of DNA. He used puss on bandaids,after he further examined the properties and composition of the substances and showed that it differed from proteins. Due to its occurrence in the cells' nuclei, he named the substance a nucleon, a term still preserved in today's name deoxyribonucleic acid. -
Chargaff
Erin Chargaff discovered two rules that helped lead to the discovery of DNA. Chargaff's first rule demostrates that the DNA based pairs are equal. He discovered that there in an A for every T and C for every G, with this being said it hinted that it was the base pair makeup for DNA. Chargaff's second rule hints that the different base pairs will make up the genetic material for different species. Chargaffs rule helped watson and crick deduce the double helical structure. -
Hershey and Chase
The Hershey and Chase experiment was a series of experiments conducted to help confirm that DNA is genetic material. In their experiments, Hershey and Chase showed that when bacteriophages, which are composed of DNA and protein, infect bacteria, their DNA enters the host bacterial cell, but most of their protein does not. Also during the experiment they injected chemical tracers that resembles proteins proving this method. -
Watson and Crick
Watson and Crick founded the double helix in 1953. It was structured to have the shape of a twisted ladder. Watson had unclear ideas of what the model really looked like,she just knew that it had a phosphate group and two nucleotides. A model was made and it failed completly. Crick used Chargaff's rule to add to the structure and it was almost immediately accepted. Chargaff's rule helped them understand the placement of the structure and where everything went, creating a twisted ladder shape. -
Franklin
Franklin contributed to the discoveries of Watson and Crick, but also went a step further with it. Around 1951, she started taking X-ray diffraction photographs that magnified the view of the double helix. Each one picture were soaked in water and once she tested it she realized that the DNA strand had two sides. When Watson saw the picture he immediately realized that was evidence to back up his discoveries. Franklin's X-rays added onto there theory by having a picture to prove there evidence. -
Meselson & Stahl
Meselson & tried to find ways to disprove Watson and Cricks semiconservative replication. They both had experimental proof of the replication process. They did this through a process called density gradient centrifugation, which uses centrifugal forces to separate the molecules based on their densities. This is the result of splitting DNA. Stahl also help him discover that at this point cells recognize there DNA and can repair themselves. -
Citation
"Friedrich Miescher and the Discovery of DNA." Developmental Biology. U.S. National Library of Medicine, 2004. Web. 23 Jan. 2017. "Erwin Chargaff." Wikipedia. Wikimedia Foundation, 2017. Web. 23 Jan. 2017. Hershey–Chase Experiment." Wikipedia. Wikimedia Foundation, n.d. Web. 23 Jan. 2017. Rosalind Franklin: Biography & Discovery of DNA Structure." LiveScience. Purch, n.d. Web. 23 Jan. 2017. "Pearson - The Biology Place." Pearson - The Biology Place. Pearson Education, n.d. Web. 23 Jan. 2017. -
Citation 2
"Discovery of DNA Double Helix: Watson and Crick." Nature.com. Macmillan Publishers, 2008. Web. 23 Jan. 2017. Pictures: "Redirect Notice." Redirect Notice. N.p., n.d. Web. 23 Jan. 2017.
"Redirect Notice." Redirect Notice. N.p., n.d. Web. 23 Jan. 2017.
"Redirect Notice.cell." Redirect Notice. N.p., n.d. Web. 23 Jan. 2017.
"Redirect Notice." Redirect Notice. Chargaff, n.d. Web. 23 Jan. 2017.
