-
Miescher
Miescher isolated nuclein DNA with associated proteins from the cell's nucleus. He identifies DNA as a distinct molecule. He did this in a laboratory by collecting used bandages, then he did experiments and isolated a new molecule, nuclein. He contributed to the study of DNA because his discovery revealed DNA as a molecule. -
Chargaff
Through experimentation, Chargaff discovered that the amounts of adenine and thymine are almost always equal, as are the amounts of guanine and cytosine. He also discovered that the amounts of the four nitrogenous bases vary from one species to another, hinting that DNA could be the genetic material rather than protein. His discoveries helped lead to the discovery of the DNA structure, the double helix. -
Hershey and Chase
Using Hershey-Chase experiments, Hershey and Chase discovered that genetic material is found in DNA. This discovery contributed to the study of DNA because most scientist believed that genetic material was stored in proteins due to proteins being so diverse in cells. -
Franklin
Franklin's discovery contains clues of how the DNA molecule is structured. By using x-ray diffraction, she stretched DNA fibers in a thin glass tube so that they were parallel, then aimed a powerful x-ray beam at the DNA. Her x-ray suggest that there are two strands in the DNA structure and that the nitrogenous bases are near the center. -
Watson and Crick
Watson and crick discovered the double helix, which is the true structure of the DNA molecule. They did this by building three dimensional models of the molecules out of cardboard and wire, and by using Franklin's x-ray photo. They contributed to the knowledge of DNA because their discovery clarified the structure of the molecule since no one knew how DNA was shaped. -
Meselson and Stahl
Through multiple experiments based of Watson and Crick's double helix, Meselson and Stahl discovered that DNA replication was semi conservative. Their discovery helped cement the concept of the double helix
