The Discovery of DNA - Gustin, Ben

Friedrich Miescher

1869

In 1869, Friedrich Miescher discovered DNA as a distinct molecule through a process where he would separate the nuclein from the nucleus of a cell. An interesting fact about this experiment is that one of his sources for cells was pus.

Frederick Griffith

1928

In 1928, Frederick Griffith conducted experiments where he would inject certain varieties of pneumonia bacteria. This proved the idea of Transformation which was about how DNA carries genetic information. Something interesting about this experiment was that mice were used as subjects.

Oswald Avery, Maclyn McCarty, and Colin McCleod

1944

In 1944, Oswald Avery, Maclyn McCarty, and Colin McCleod further proved Griffith's idea of Transformation by experimenting with the same bacteria as Griffith. Something interesting about this experiment is that Chloroform was used as a key component.

Barbara McClintock

1944

In 1944, Barbara McClintock discovered mobile or “jumping” genes after she found a chromosome-breaking locus that had the ability to alter its position in the chromosome. An interesting fact about her discovery is that she found it while studying maize.

Erwin Chargaff

1949

In 1949, Erwin Chargaff discovered that the bases in DNA, guanine, cytosine, adenine, and thymine were all equal to one another. The way in which he discovered these bases' compositions in DNA was through careful experimentation with his own adapted version of paper chromatography. What is interesting about this discovery is that the four bases are what do the actual coding of our genes.

Linus Pauling

1951

In 1951, Linus Pauling discovered the helical shape of DNA while playing around with nucleic acids. An interesting fact about this discovery is that it helped lead to the eventual discovery of the double helix structure of DNA.

Alfred Hershey and Martha Chase

1952

In 1952, Alfred Hershey and Martha Chase proved that DNA was genetic material and that proteins were in fact not genetic material. The experiment utilized radioisotopes as tracers on viruses. Something interesting about this experiment is that the viruses injected their DNA into the host bacteria used.

Rosalind Franklin and Maurice Wilkins

1952

In the May of 1952, Rosalind Franklin and Maurice Wilkins used x-rays to try and uncover the structure of DNA. Franklin one day captured Photo 51, the image that depicts the double helix structure of DNA. What is interesting about this discovery is that Franklin was not given credit for her research.

James Watson and Francis Crick

1953

Using the research of Rosalind Frank, Watson and Crick deduced that DNA’s structure was that of a double helix with the bases forming a ladder that connects the two helices with each rung. An interesting fact about their discovery is that they did not credit Rosalind for her work.

Frederick Sanger

1958

In 1958, Sanger discovered the structure of the insulin molecule . He did this by obtaining a protein sequence and guessing that if the proteins were arranged in a certain order, then the DNA and genes were as well. An interesting fact about this experiment is that insulin is a molecule key to lowering the blood sugar in people and if there is too little in a person, it can cause diabetes.

Matthew Meselson and Franklin Stahl

1958

In 1958, Meselson and Stahl invented a technique of density gradient centrifugation that they used to prove the semi-conservative replication of DNA. An interesting fact about their discovery is that the experiment was conducted due to debates between scientists surrounding the issue of how DNA replicated itself.

Paul Berg

1972

In 1972, Paul Berg conducted various DNA experiments with a virus. He was able to take DNA from bacteria and insert it into the virus’ DNA. By doing this, Berg created the first hybrid DNA molecules. An interesting fact about this discovery is that the specific virus Berg used was the tumor virus SV40.

Kary Mullis

1985

In 1985, Kary Mullis invented the process called polymerase chain reaction, which allows large amounts of DNA to be replicated in a short period of time. This is done by applying heat, causing the two DNA strands to separate allowing the added DNA building blocks to bond. An interesting fact about this discovery is that it can now be used in forensics.

J. Craig Venter

2001

In 2001, Venter helped to make the first map of the human genome as a part of the Human Genome Project. An interesting fact about this is that the project was announced with former U.S. president Bill Clinton.