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Miescher
Miescher is actually the man that discovered DNA. Miescher was experimenting with white blood cells when he discovered an unknown type of molecule which happened to be DNA. Miescher named the molecule nuclein but did not think the molecule was the carrier of heredity information. In order to make his discovery he collected bandages with pus on them and lysed the cells with an alkaline solution which resulted in the nuclei precipitating out of the solution. -
Chargaff
Chargaff discovered that the amount of purines and pyrimidines in DNA must be equal.In order to make his discovery, Chargaff isolated the DNA from the nucleus and separated the purines and pyrimidines using paper chromatography.Chargaff discovered that the amount of Adenine and Thymine were the same and the amount of Cytosine and Guanine were the same.Chargaff argued that although there are only 4 nucleic acids, the nucleic acids could be in many different proportions depending on the species. -
Franklin
Franklin’s X-ray diffraction photos of DNA led to Watson and Crick’s discovery of DNA having a double helix. Franklin’s contribution to the discovery of the structure of DNA is overlooked. The photo that shows the DNA is called Photo 51. Photo 51 was taken by X-ray diffraction Franklin’s discovery jumpstarted the era of DNA research. -
Hershey & Chase
Hershey&Chase conducted an experiment that discovered that DNA contains the genetic code material and not proteins.Hershey&Chase made this discovery by growing viruses in 2 isotonic mediums, allowing it to infect E. coli, and then separating them from one another.The pellet was radioactive when infected by the DNA meaning the genetic material was passed on by DNA.This discovery was a breakthrough in the study of reproduction because it made it known exactly what passes on genetic information. -
Watson & Crick
Watson and Crick worked together to conclude that Deoxyribonucleic-acid (DNA) is structured as a double-helix polymer. The two did not perform any DNA experiments of their own but instead used their scientific knowledge in physics, viral and bacterial genetics, and X-ray crystallography and their intuition to come to the conclusion that DNA has a double-helix structure. Watson and Crick’s discovery helped show that DNA can reproduce itself during cell division. -
Meselson & Stahl
Meselson and Stahl experimented with DNA replication.The results that Meselson and Stahl received from their experiment supported the hypothesis that DNA replication was semiconservative.Semiconservative replication is the formation of 2 identical copies of the original double stranded molecule.Meselson and Stahl were able to come to this conclusion by labeling the DNA of bacteria(E.coli)using isotopes of nitrogen.Meselson and Stahl’s discovery helped the science world know how DNA behaved.
