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Friedich Miescher
Friedrich Miescher was a chemist who was the first to describe DNA. In 1869, Friedrich Miescher extracted DNA from cell nuclei to determine that DNA was not a protein. He also found that DNA was rich in nitrogen and phosphorus. -
Frederick Griffith
In 1929, Frederick Griffith conducted experiments on mice using two strains of pneumonia-causing bacteria. From this experiment, Griffith discovered that material could be transferred from dead cells to live cells. -
Oswald Avery, Maclyn McCarty & Colin McCleod
Oswald Avery, Maclyn McCarty, and Colin McCleod did an experiment to identify the substance that was transferred from the dead cells to the live cells in Griffith's experiment. They treated the cells with lipid, protein, and RNA-destroying enzymes. They found that this substance could not have been either of those, and so it had to be DNA. -
Barbara McClintock
Barabara McClintock discovered the term for genes to be mobile. While discovering about genes being mobile, she found other mobile elements(transposens). Depending on where the mobile elements were inserted, they could reverse the gene. The genes expressions would also be reversed. -
Alfred Hershey and Martha Chase
Alfred Hershey and Martha Chase carried out a series of experiments using bacteriophage. They found that bacteriophage injects DNA into bacteria to infect it, not protein. This proved that DNA, not protein as previously believed, transmits hereditary information. -
Erwin Chargaff
Erwin Chargaff discovered that the amounts of thymine and adenine in DNA are equal and the amounts of cytosine and guanine in DNA are equal. This is known as Chargaff's First Rule. Chargaff's Second Rule is that DNA of different species differs in proportions of adenine and guanine. -
Rosalind Franklin & Maurice Wilkins
Rosalind Franklin and Maurice Wilkins used x-ray crystallography to produce an image of DNA. This image, known as Photo 51, showed the structure of DNA. The image would allow Watson and Crick to later create a model of the double helix which would be published in 1953. -
Linus Pauling
In 1953, Linus Pauling proposed his version of the structure of DNA along with Robert Corey. Pauling's version of DNA structure consisted of three strands twisted around each other. He was awarded a Nobel Prize for Chemistry in 1954. -
James Watson & Francis Crick
James Watson & Francis Crick discovered/suspected the shape of DNA. The were the first to coin the term of saying DNA looked like a double helix. Watson & Crick had arguments over the requirement bonds for DNA. They also found out the size of DNA. There discovery was one of the top discoveries. -
Matthew Meselson & Franklin Stahl
Meselson & Stahl created many experiments. They ended up developing a density gradient centrifugator. Then, they used that ro prove that DNA was replicated. There experiments and creating the centrifugator helped prove Watson and Crick right. -
Frederick Sanger
Fredrick Sanger solved the problem of sequencing DNA. He also investigated ways to sequence DNA. This led to many techniques being found. Some of the techniques that were being used are techniques we may even use in todays world. -
Paul Berg
Paul Berg was the first to assemble a DNA molecule. He assembled a mole that had genes from different types of organisms. He didn't work on the recombinant molecules by himself. He had other biochemist helping him to create these molecule. Berg mainly made hybrid DNA molecules.
(picture is of recombinant DNA) -
Kary Mullis
Kary Mullis invented the idea of the polymerase chain reaction. Also known as the PCR. PCR amplifies certain DNA sequences from very small amounts of genetic material. This invention won a Nobel Peace Prize. -
J. Craig Venter
John Craig Venter began the race of sequencing the human genome. He was very focused on the genome in the early 1990's and ended up developing a method. The EST method was the method and it was cheaper and a lot faster than the Human Genome Project. This method was very effective.
