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Miescher's Discovery of Nuclein
In 1870, Miescher began experiments on leucocytes to begin explaining the building blocks of life. He observed the proteins within the cell and saw an unknown substance that didn't have the similar properties of the protein. This was the first crude purification of DNA and observed its occurrence in the nuclei of the cell. He would then call the substance "nuclein". -
Mendel's Theories are Rediscovered by Researchers
What Mendel's theories are is that they are the simple principles of heredity. In the 1860s he made this discovery by researching plants and their offspring. With the evidence of heredity of plants, he applied this theory to all complex organisms. He published this theory in 1866 and later on died in 1884. His theories wouldn't be largely recognized until 1902. -
Garrod associates Mendel's Theories with Human Disease
Garrod studied the human disorder alkaptonuria. While doing so, he collected family history from his patients. Using Mendel's theories, he concluded that certain diseases were caused by errors in heredity. -
Griffith's Experiments on Bacteria
In his experiments, he tested on mice using two strands of Pneumococcus bacteria. Some of the bacteria left the mice with small symptoms while other time it killed its host. It was then rendered ineffective after killing its first host. In doing so, Griffith discovered the transforming principle. -
Avery identifies DNA as nucleic acids
Avery was attempting to discover what substance makes certain bacteria that are harmless into something lethal. He and his colleagues took twenty gallons of bacteria and purified it until all that was left was a substance. That substance was not a protein or a carbohydrate but a nucleic acid and was further shown to be DNA. -
Chargaff Discovers DNA Differs between Different Species
Chargaff began his work on the chemistry of nucleic acids after reading Avery's scientific paper on DNA. He began to analyze the nitrogen bases and sugars in the DNA of different species. Chargaff then concluded that the DNA in different species differs. -
Franklin & Wilkins Photograph DNA
Using X-ray diffraction techniques, Franklin used it to photograph DNA and suggested that it was in a helix-like structure. The original samples of DNA were given to Wilkins by Signer. -
Hershey & Chase Discover DNA in Bacteria and Viruses
In 1952, Hershey and Chase conducted experiments on cells with DNA viruses. Through their experiments, it showed that viruses and bacteria infected its hosts with DNA. -
Watson & Crick find the Structure of DNA
Watson and Crick used X-ray data and model building to analyze the structure of DNA. Even though Franklin's photos played a huge role in finding the structure of DNA, only three could share the Nobel Prize. She then later on died of cancer in 1958.