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Miescher
Miescher isolated phosphate-rich chemicals from the nuclei of white blood cells and called it nuclein. How he did this is he filtered cells with sodium sulfate, purified the nuclei, put the nuclei through alkaline extraction followed by acidification, and formed a precipitate he called nuclein (aka DNA). This paved the way for DNA to be identified as the carrier of inheritance. -
Miescher
Miescher isolated phosphate-rich chemicals from the nuclei of white blood cells and called it nuclein. He found this by filtering cells with sodium sulfate, purifying the nuclei, putting the nuclei through alkaline extraction followed by acidification, and formed the precipitate Miescher called nuclein (or DNA). This paved the way for identification of DNA as the carrier of inheritance. -
Chargaff
Chargaff made two key discoveries about DNA which were that different species have different amount of bases or A:G varies from species to species and that an organism has a fixed ratio of bases or A:T is 1:1 and C:G is 1:1. He discovered this by isolating DNA and separating purines from pyrimidine based on solubility. Overall, this proved that DNA is the primary constitute of a gene. -
Chargaff
Chargaff discovered two key principles of DNA- that different species have different amount of bases or A:G varies from species to species and organisms have a fixed ratio of bases or A:T is 1:1 or C:G is 1:1. He found this by isolating DNA and separating purines from pyrimidine based on solubility. This showed that DNA is the primary constituent of the gene. -
Hershey and Chase
Hershey and Chase confirmed that DNA is genetic material through a series of experiments involving viruses that showed that in growth protein serves no function while DNA does. This proved protein was not hereditary genetic material which paved the way to Watson and Crick's that DNA is the hereditary material. -
Rosalind Franklin
Franklin took an incredibly important, X-ray picture of DNA which was made by an X-ray technique that allowed DNA to not be crystallized as DNA does not like to take a crystallized form but X-ray pictures often require the object to be crystallized. Photo 51 (as the picture was called) ultimately proved that DNA takes a double helical structure and was very important for future research such as Watson and Crick's findings. -
Hershey and Chase
Hershey and Chase confirmed that DNA is genetic material through a series of experiments using viruses that showed that in growth protein has no function while DNA does. This proved that protein was hereditary genetic material which paved the way to Watson and Crick's hypothesis that DNA was the hereditary material. -
Franklin, Rosalind
Franklin took the immensely important X-ray picture of DNA (Photo 51) by using an X-ray technique that allowed you to see the X-rayed object without crystallizing it-as DNA did not prefer the crystallized form. This photo proved DNA was a double helical structure which led the way to many scientific discoveries regarding DNA. -
Watson and Crick
Watson and Crick discovered that DNA took a 3-D, double helix structure and ran anti-parallel, and they made a correct model of the DNA structure. They did this by using cardboard cutouts to represent the 4 bases and other nucleotide subunits and organized different atomic configurations to figure out the composition of DNA. They showed how DNA runs 5' to 3' and how nucleotides are linked by phosphate groups, a very important realization about DNA. -
Watson and Crick
These two discovered that DNA was anti-parallel and had a double helix structure; they also created a model of DNA. They made this discovery by using cardboard cutouts to represent 4 bases and the other nucleotide subunits and organized different atomic configurations to figure out the composition of DNA. This showed how DNA runs 5' to 3' or antiparallel and how nucleotides are linked by phosphate groups. -
Meselson and Stahl
They proved DNA replication is semiconservative- replicating double stranded DNA helix results in two new double stranded DNA with an original strand and a new one. This was proved through an experiment involving DNA being extracted from 14N DNA and 15N DNA periodically and they found that DNA from cells after 2 replications consisted of equal amounts of DNA with 2 different densities. This showed that each strand acts as a template for the synthesis of a new strand in DNA replication. -
Bibliography 5
Wikipedia contributors. "Hershey–Chase experiment." Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 18 Jan. 2017. Web. 24 Jan. 2017. -
Bibliography 6
Wikipedia contributors. "Friedrich Miescher." Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 19 Oct. 2016. Web. 24 Jan. 2017. -
Bibliography 1
Pray, Leslie A. "Discovery of DNA Structure and Function: Watson and Crick." Www.nature.com. Nature Education, 1 Jan. 2008. Web. 23 Jan. 2017. <www.nature.com/scitable/topicpage/discovery-of-dna-structure-and-function-watson-397>. -
Bibliography 2
Martine Oudenhoven. "Making Life Crystal Clear." ASU - Ask A Biologist. 19 Aug 2012. ASU - Ask A Biologist, Web. 20 Jan 2017. http://askabiologist.asu.edu/Rosalind_Franklin-DNA -
Bibliography 4
Wikipedia contributors. "Meselson–Stahl experiment." Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 3 Jan. 2017. Web. 24 Jan. 2017. -
Bibliography 3
"Erwin Chargaff." Famous Scientists. famousscientists.org. 9 Aug. 2016. Web. 1/24/2017
<www.famousscientists.org/erwin-chargaff/>.
"Erwin Chargaff." YourDictionary, n.d. Web. 24 January 2017. http://biography.yourdictionary.com/erwin-chargaff.
