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Friedrich Miescher
MIescher did research on white blood cells or lymphoid cells. He discovered nuclein. He found nuclein is made of hydrogen, oxygen, nitrogen and Phosphorous. he later got a job in a university which his father previously had before him. -
Fredrick Griffith
Griffith isolated two strands of bacteria. R strand is harmless and S strand is lethal. He did a series of experiments with these strands on mice and saw material could be transferred from dead S strands to alive R strands. the experiment was permanent and heritable. -
Barbara McClintock
She experimented on the genes of maize. In doing this, she discovered what is known as Transposable Elements, also known as jumping genes. These genes were discovered to be able to move to and from different parts of the chromosomes. They were also shown to be responsible for mutations and pigments of the corn kernels and other features. It was not until the late 1960's that it was discovered that this genetic material was in fact DNA. -
Oswald Avery, Maclyn McCarty, &Colin McCleod
They discovered that DNA was hereditary but not the only hereditary material. in order to be a hereditary material you have to have certain proteins in oder to function. The material must be able to encode large amounts of information to build a cell. -
Alfred Hershey and Martha Chase
Hershey and Chase proved that DNA, not protein is the first property of hereditary material. They based tons and tons of experiments off of the fact that proteins had more sulfur than phosphorous and DNA had more phosphorous than sulfur. They are famous for something called the Blender experiment. -
Linus Pauling
Pauling researched another scientists information of nucleic acids. He knew the information was wrong because DNA is a helical shape with phosphate groups in the middle. He discovered that DNA was three stranded. Pauling also unfortunately died of cancer as well. -
Erwin Chargaff
Chargaff discovered that the number of guanine is equal to the number cytosine. He also discovered that adenine is equal to the number of thymine. These are at the base of DNA. Then he discovered that all of those vary from one species to another. After Watson, Crick, and Wilkins received their nobel prizes, he sent letters about his exclusion. -
James Watson & Francis Crick
Watson and Crick worked in tandem to study the structure of DNA. They used X-ray diffraction to study the DNA, and discovered the very structure and shape of the DNA molecule. It was determined to be a double helix. Both were awarded a Nobel Prize in medicine. Francis Crick may have passed in 2004, but James Watson is still alive at the age of 90. -
Rosalind Franklin and Maurice Wilkins
Franklin and Wilkins obtained the first clearly taken X-Ray of DNA. they looked at the diffractions and different qualities and traits. Specifically the physical and chemical traits passed down through different organisms and generations. Unfortunately, Rosalind went on to die of cancer a little while later. Wilkins went on to win a nobel prize. -
Frederick Sanger
He discovered and identified the free amino groups within insulin. He also found various ways to order them. He proved that proteins were ordered molecules, and that the genes and DNA that create these proteins must have their own order or sequence. He noted that a gene is a discrete and specific sequence of DNA nucleotides. -
Matthew Meselson & Franklin Stahl
Meselson and Stahl expanded upon Watson and Crick's experiments on DNA and how it is structured by researching how it is formed. To do this, they began by growing a E. coli which contained a heavy isotope of nitrogen (N15). After that, the bacteria were switched to a medium containing light nitrogen (N14). They measured the density of the DNA using a method Meselson created himself called density gradient centrifugation. -
Paul Berg
Paul Berg produced the first recombined DNA molecule. To do this, he genetically engineered a virus by splicing 2 DNA molecules. One was from a tumor virus, while the other originated from a plasmid carrying genes from the E. Coli virus. With the help of David Jackson and Robert Symons, he discovered that mammalian viruses could, in fact, pick up genes and transfer the to new cells the same way bacterial cells can. -
Kary Mullis
Kary Mullis created the polymerase chain reaction (PMR). In this process, a small amount of DNA can be copied in large quantities over a short period of time.By applying heat, the DNA molecule's two strands are separated and the DNA building blocks that have been added are bonded to each strand. With the help of the enzyme polymerase, new DNA chains are formed.
