Scientists of DNA

By nicholas.adams2020

  • Miescher

    Miescher
    Friedrich Miescher isolated the first crude preparation of DNA from bandage pus and named in "nuclein". Along with most scientists, Miescher believed that proteins were the molecules of heredity. It would be years before the role of nucleic acids were recognized. However, Miescher laid the groundwork for the molecular discoveries that followed.

  • Chargaff

    Chargaff
    Erwin Chargaff was a biochemist and was also a professor of biochemistry at Columbia University medical school. Through careful experimentation, Chargaff discovered two rules that helped lead to the discovery of the double helix structure of DNA. One 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. For this research, Chargaff is credited with disproving the tetranucleotide hypothesis.

  • Franklin

    Franklin
    In 1951, Franklin was offered a 3-year research scholarship at King's College in London. With her knowledge, Franklin was to set up and improve the X-ray crystallography unit at King's College. Maurice Wilkins was already using X-ray crystallography to try to solve the DNA problem at King's College. Working with a student, Raymond Gosling, Franklin was able to get two sets of high-resolution photos of crystallized DNA fibers. From this she deduced the basic dimensions of DNA strands.

  • Hershey and Chase

    Hershey and Chase
    Hershey and Chase conducted an experiment that helped to confirm that DNA is genetic material. While DNA had been known to biologists since 1869, many scientists still assumed at the time that proteins carried the information for inheritance because DNA appeared simpler than proteins. 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

    Watson and Crick
    Though DNA was discovered in 1869, its crucial role in determining genetic inheritance wasn’t demonstrated until 1943. In the early 1950s, Watson and Crick were only two of many scientists working on figuring out the structure of DNA. Linus Pauling suggested an incorrect model at the beginning of 1953, prompting Watson and Crick to try and beat Pauling. On the morning of February 28, they determined that the structure of DNA was a double-helix polymer.

  • Meselson and Stahl

    Meselson and Stahl
    Meselson and Stahl conducted an experiment which supported the hypothesis that DNA replication was semiconservative. In semiconservative replication, , each of the two new double-stranded DNA helices consisted of one strand from the original helix and one newly synthesized.This experiment proved the semiconservative hypothesis, proposed by Watson and Crick, the two strands of a DNA molecule separate during replication. Each strand then acts as a template for synthesis of a new strand.