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Friedrich Miescher
Miescher determined that the nuclein in pus cells was made up of Hydrogen, oxygen, nitrogen, and phosphorus and the was a unique ratio between nitrogen and phosphorus. In the experiment that he conducted he used the cells of salmon sperm instead of puss cells. -
Frederick Griffith
A scientist that studies bacteria. Trying to find a cure for Pneumonia. showing that bacteria can get DNA through transformation. He used mice for this experiment, his favorite animal. He was able to get live ll-R and ll-S stains of S Pneumonia. -
Oswald Avery, Maclyn McCarty and Colin McCleod
These people identified deoxyribonucleic acid (DNA), as the "transforming principle" responsible for specific characteristics in bacteria. In the experiment, they observed mice that were injected with a live but harmless form of Pneumococcus and also with a lethal form of the bacteria. Some of the mice eventually got infected and died and the lethal bacteria was able to be recovered depending on the bacteria. -
Erwin Chargaff
His experiment proved that DNA remains the same within an organism but differs between different organisms. His experiment established that these two types of bases appeared in a one-to-one ratio. He was able to prove a one-to-one ratio between adenine and thymine and guanine and cytosine. He concluded that DNA composition is species. -
Linus Pauling
Pauling became the founder of molecular biology due to his discovery of the spiral structure of proteins. Heproposed the idea of the triple helix struture of DNA. By using his knowledge of X-Ray crystallography and his understanding of chemistry rules, he determined how amino acids fit together to make proteins. He used paper to make models and eventually figured out the structure of the alpha helix of globular proteins. -
Alfred Hershey & Martha chase
They conducted a series of experiments. They helped to confirm that DNA is genetic material. Viruses were grown in one of two isotopic mediums in order to radioactively label a specific viral component. They were then allowed to infect a bacterium then separated via centrifugation larger bacteria formed a solid pellet small remained supernatant. Pellet found radioactive when affected. -
James Watson and Frances Crick
After many attempts at finding the structure of DNA, they found a model that worked. They figured it out cause A=T and C=G and figured out the double helix structure of DNA. This happened in about 2hrs. The used other scientists' information such as image 51 to for their theory. -
Rosalind Franklin and Maurice Wilkins
These scientists contributed to the discovery of the structure of DNA. Franklin created images of DNA using X-Ray crystallography. The idea of crystallography was first created by Wilkins. Franklins image that shows the repetitive structure of DNA and Wilkins new technology will later contribute to other scientists discovery of the structure of DNA. -
Frederick Sanger
He developed techniques for sequencing proteins and DNA. He earned his Ph.D by studying the metabolism of the amino acid lysing and and then later moved on to study insulin. Sanger detirmined insulin's amino acid sequence, which had never been fone before. sing chemistry and chromatography he developed a method used to read the amino acid sequence of insulin. He also found that this protein is actually made up of two amino acid chains linked together by disulphide bonds. -
Matthew Melson and Franklin Sahl
After Watson and Crick found the double helix structure the next step was to find out how it made a copy of itself. To start there were three proposals semi-conservative, conservitive,dispersive and they found out that semi-conservative was right. They grew bacteria in heavy nitrigen and spun it in the nitro fuse then looked at the desity to find out the right one. -
Paul Berg
His contribution to DNA was the technique of slice and join DNA molecules. This laid down the foundation for the recombinant DNA Technology. The first recombinant DNA molecule was discovered by his student Janer Martz. -
Barbara McClintock
She spent her career observing and experimenting with variations in the in the coloration of corn kernels. She discovered that genetic information is not locked to a single spot. By tracing the pigment in corn and using a microscope to examine large chromosomes she found 2 genes she called controlling elements. These genes control the genes that were responsible for pigmentation. Controlling elements could move along the chromosome, and hence affecting the genes around it and causing a mutation. -
Kary Mullis
Mullis invented the polymerase chain reaction (PCR). This is a technique that amplifies a specific DNA sequence from very small amounts of genetic material. He later won the Nobel Prize for his discovery of PCR. -
J. Craig Venter
His contribution to the discovery of DNA was that he mapped out the sequenced human DNA. With the help of Francis Collins they were able to individually complete what they call the human genome project, it was finished in 2000. President Bill Clinton and British Prime minister Tony Blair made a joint desition that all genome info should be free to the public.
