-
Miescher
DNA and proteins are key molecules of the cell nucleus.Friedrich Miescher isolated "nuclein," DNA with associated proteins, from cell nuclei. He was the first to identify DNA as a distinct molecule. He experimented and isolated a new molecule nuclein from the cell nucleus. He determined that nuclein was made up of hydrogen, oxygen, nitrogen and phosphorus and there was an unique ratio of phosphorus to nitrogen.Miescher laid the groundwork for the molecular discoveries that followed. -
Chargaff
Chargaff is best known for his discovery of DNA base ratios,also known as Chargaff’s rules.Through experimentation,Chargaff discovered two rules that helped lead to the discovery of the double helix structure of DNA. The first rule was that in DNA the number of guanine units equals the number of cytosine units, and the number of adenine units equals the number of thymine units.One extremely important result of his discovery was that it help determined of the structure of DNA. -
Hershey and Chase
The Hershey–Chase experiments were a series of experiments conducted by Alfred Hershey and Martha Chase that helped to 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. -
Watson and Crick
The double helix,the twisted-ladder structure of DNA,is what scientist contributed.Watson and Crick were using X-ray diffraction to study DNA.The discovery helped to produce new and powerful scientific techniques,recombination DNA research,genetic engineering,rapid gene sequencing, and monoclonal antibodies.Major advances in science, namely genetic fingerprinting and modern forensics, the mapping of human genome, and unfulfilled of gene therapy,all have their origins in Watson and Crick's work. -
Meselson and Stahl
Meselson and Stahl had the experimental proof for the semi-conservative replication of DNA. They did this by inventing a new technique called density gradient centrifugation, which uses centrifugal force to separate molecules based on their densities. Their classic paper was published in 1958 and their experiment has been called "one of the most beautiful experiments in biology." -
Franklin
Franklin, discovered part of "The Double Helix" and it was the one bit of information that Crick needed to complete an accurate model of the structure of DNA. Photo 51 was proof that DNA’s helical structure had two strands attached in the middle by the phosphate bases. Franklin made the discovery by the DNA shown in the X-ray images.Without Franklin's help,scientist would not have been able to complete the DNA molecule. -
citation
The Francis Crick Papers: The Discovery of the Double Helix, 1951-1953." U.S. National Library of Medicine. National Institutes of Health, n.d. Web. 23 Jan. 2017.
BBC - History - Crick and Watson." BBC News. BBC, n.d. Web. 23 Jan. 2017.
"Erwin Chargaff." Wikipedia. Wikimedia Foundation, n.d. Web. 23 Jan. 2017.
Hershey–Chase Experiment." Wikipedia. Wikimedia Foundation, n.d. Web. 23 Jan. 2017. -
citation
Rosalind Franklin: Biography & Discovery of DNA Structure." LiveScience. Purch, n.d. Web. 23 Jan. 2017.
"Chargaff, Erwin." Complete Dictionary of Scientific Biography. Encyclopedia.com, n.d. Web. 23 Jan. 2017.
DNA and Proteins Are Key Molecules of the Cell Nucleus." The Josiah Macy, Jr. Foundation, 2002 - 2011,. Web. 23 Jan. 2017 -
citation
Concept 20 A Half DNA Ladder Is a Template for Copying the Whole." Matthew Stanley Meselson :: DNA from the Beginning. The Josiah Macy, Jr. Foundation, 2002 - 2011. Web. 23 Jan. 2017. -
citation
Concept 20 A Half DNA Ladder Is a Template for Copying the Whole." Matthew Stanley Meselson :: DNA from the Beginning. The Josiah Macy, Jr. Foundation, 2002 - 2011. Web. 23 Jan. 2017.
"Concept 15 DNA and Proteins Are Key Molecules of the Cell Nucleus." Friedrich Miescher :: DNA from the Beginning. N.p., n.d. Web. 23 Jan. 2017.
