Biology DNA Timeline by

Friedrich Miescher

snarapar — 2024-02-12 02:06:53 UTC

In 1869, Friedrich Miescher discovered DNA, developing techniques for its extraction. He did his research with white blood cells by isolating nuclein from the nucleus. He isolated a material rich in phosphorus from a human pus cell. His paper on his research wasn’t published until 1871.

https://www.dnaftb.org/15/bio.html

Frederick Griffith

snarapar — 2024-02-12 02:09:48 UTC

In 1928, he conducted an experiment that discovered that DNA acts as a carrier of genetic information. He injected 2 strains of Streptococcus pneumonia in mice. The virulent bacteria was heat killed, and he found that the mice intoxicated with both bacteria’s died even after heat was applied. He concluded that virulent changed a virulent bacteria and that DNA was transferred.

https://www.britannica.com/biography/Frederick-Griffith

Oswald Avery

snarapar — 2024-02-12 02:10:51 UTC

In 1944, he said that the transforming substance and the genetic material of the cell was DNA. He expanded in Griffith’s experiment which used phenotype of 5 pneumonia cells expressed on blood agar instead of rats. They removed lipids and sugars from the heat killed 5 cell solutions, added enzymes to destroy any protein, RNA and DNA, then added living IIR cells to see if any 5 cells reappear. Only DNA did so DNA is the genetic material.

https://www.britannica.com/biography/Oswald-Avery

Erwin Chargaff

snarapar — 2024-02-12 02:13:01 UTC

He identified that there was a 1:1 ratio in DNA’s bases and was published in 1950. He conducted a series of experiments by separating substances found in DNA using paper chromatography and UV spectrophotometers to count the amount of each base in each sample.

https://www.nature.com/scitable/topicpage/discovery-of-dna-structure-and-function-watson-397/#:~:text=Chargaff%27s%20realization%20that%20A%20%3D%20T,for%20the%20structure%20of%20DNA.

Maurice Wilkins

snarapar — 2024-02-12 02:14:42 UTC

In 1951, he was involved with the x-ray diffraction work on DNA and was successfully able to isolate single fibers of DNA. Also he was involved with the development of the photo 52 along with Franklin and Gosling. He alerted Watson and Crick about photo 51 which helped then build their model of DNA.

https://www.whatisbiotechnology.org/index.php/people/summary/wilkins#:~:text=Wilkins%20is%20most%20well%2Dknown,double%2Dhelix%20structure%20of%20DNA.

Martha Chase and Alfred Hershey

snarapar — 2024-02-12 02:16:21 UTC

In 1952, they performed experiments that build on the theory that DNA was the genetic material. They used 2 bacteria’s and tagged one batch of the TZ’s proteins and another for DNA with radioactive sulfur from protein and phosphorus for DNA. Measured radioactivity in each batch of bacteria and found that most radioactivity was found in E. Coli when DNA was tagged. The experiment concluded that DNA was the molecule for genetics.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7961593/#:~:text=In%201952%2C%20Alfred%20Hershey%20and,DNA%20as%20the%20genetic%20material.

Rosalind Franklin

snarapar — 2024-02-12 02:16:58 UTC

She suspended a tiny DnA fiber and put it under a x-ray beam for 100 hours of exposure under controlled humidity and found her research in 1952. The rays were diffracted by the electrons in the atoms of the fiber and produced a pattern on a photograph plate. She used mathematical computers to analyze this pattern and found out the shape of DNA, the double helix.

https://www.kcl.ac.uk/the-structure-of-dna-how-dr-rosalind-franklin-contributed-to-the-story-of-life-2#:~:text=The%20discovery%20of%20the%20structure,development%20of%20all%20living%20organisms.

Linus Pauling

snarapar — 2024-02-12 02:18:46 UTC

He wrote “Nucleic Acids” in 1953. The used x-ray diffraction patterns and electron microscopy they falsely predict that DNA is a triple helix made up of three nucleic acid strands. He believed that phosphate groups made up the core of the DNA and where attached to groups of sugar through hydrogen bonds that the nucleotides bases faced the outside. He also helped prevent the inheritance of genetic disorders.

https://embryo.asu.edu/pages/proposed-structure-nucleic-acids-1953-linus-pauling-and-robert-brainard-corey

James Watson and Francis Crick

snarapar — 2024-02-12 02:19:46 UTC

In 1953, they discovered that DNA was a three dimensional double helix structure made from two twisted strands of nucleotides and that bases connected the strands through hydrogen bonds. They stole one of the photos from Rosalind and used it to create their model in 9153.

https://www.pbs.org/wgbh/evolution/library/06/3/l_063_01.html#