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Friedrich Miescher
Miescher was the first to identify DNA as a distinct molecule. He was assigned to research white blood cells, but he experimented, and in doing so he discovered a new molecule called nuclein which is DNA with associated proteins. Miescher isolated it from the cell's nucleus and witness a unique ratio of phosphorus and nitrogen within it. Without this discovery, it is known that DNA is a separate molecule instead of it being attached to something. -
Erwin Chargaff
Chargaff discovered 2 rules on the structure of DNA. The first rule was that the amount of bases depended on what species the DNA came from. The second rule was that # of C=G and # of A=T. He focused his attention on DNA bases in which he learned that the bases are adenine, cytosine, guanine, and thymine, and that phosphate and sugars are added to A,T,C,G to form nucleotides. Focusing on these bases, he founded the two rules. With this, he explains the how a variation of species came to be. -
Hershey and Chase
Hershey and Chase discovered that DNA carries genetic material. Hershey accepted a position at an institution in Washington where he worked with Chase. The two of them did blender experiments that revealed that DNA carries the genetic material. This experiment allowed bacteria to inject their DNA into another DNA molecule. This caused the protein to become radioactive but not the DNA even after being shook. This discovery shows everyone that their DNA won't change and why organisms have DNA. -
Rosalind Franklin
Franklin along with Wilkins were also major contributors to finding the structure of DNA. At her college, she was to improve an X-ray's crystallography. In doing so, she noticed some DNA crystallized fibers in a helical structure. Wilkins, working with Franklin, presented this information with Watson and Crick in which they took the claim of them discovering the double helix. If it wasn't for Franklin's work, Watson and Crick wouldn't have discovered DNA's structure. -
Watson and Crick
Watson and Crick discovered the structure of DNA, the double helix. California chemist Linus Pauling proposed a false model of DNA's structure, so Watson and Crick tried to beat Pauling at his own game. Then on the morning of February 28, they proposed that the structure is a double helix polymer. Without these two scientists, the world wouldn't know how genetic material stays in a cell. However, Watson and Crick discovered that DNA is a spiral of two DNA strands containing a nucleotide chain. -
Meselson and Stahl
Meselson and Stahl created a model of how DNA replicates itself called the semi-conservative model. This model suggests that the two strands from DNA gets a new strand so that when cells divide, both daughter cells have one strand from both parents. Meselson's professor gave him Watson and Crick's papers for deciphering. Stahl was working on another project but then changed to tackling Watson and Crick's hypothesis with Meselson. They worked to make the model which shows how DNA is passed down.
