-
Friedrich Miesher
Friedrich, the man who lived from 1844-1895, extracted DNA and found some interesting results that would later be the main building block for future research. He discovered how to isolate DNA from a cell by experimenting with white blood cells and that DNA is not a protein, but instead, it is highly abundant in nitrogen and phosphorous. To find this information, he used pus covered bandages that were found near his university. He graduated from the University of Basel. -
Frederick Griffith
The British bacteriologist Frederick Griffith isolated R (harmless) cells and S (dangerous) cells in mice and tested them with heat to see the results. His intention on this experiment was to test the ability of the mice to cause pneumonia, but during this test, he discovered that heat killed the S cells, but not the ability that kills the mice. As it turns out, he discovered that even though he destroyed the harmful cells, the material from the S cells transfered over to the r cells to live on. -
Barbara McClintock
She discovered that some genes could be mobile and discovered mobile elements like transposons. The "jumping genes" could move along the chromosome to a different site, and these changes affected other genes. She analyzed chromosomes of corn (maize). She was the first woman to be the sole winner of the Nobel Prize when she won in 1983. Her work was not recognized and verified until the late 1960s and 1970s. -
Oswald Avery, Maclyn McCarty, & Colin McCloed
The three scientists wanted to continue Frederick's experiment in order to find out the "transforming principle". They did this by injecting lipid and protein destroying enzymes into the S cells. Because no significant change happened, they determined the DNA was the cause of the bacteria transformations and it was a genetic material. The most intresting part of their expiriments is that cells can be altered by the DNA that is in them. -
Erwin Chargaff
He discovered that adenine and thymine are in equal proportion as well as guanine with cytosine. Even with figuring out this big of discovery, he researched more and found out that different specious have different proportions of the nucleotides. With this information, Watson, and Crick were able to make their model with an equal amount of thymine to adenine and cytosine to guanine. He did this by extracted organs from different specious and examined their DNA. -
Alfred Hershey and Martha Chase
These two scientists determined that DNA satisfies the first property of heredity and that it transmits a full complement of heredity information.They came to this conclusion by injecting a virus into a bacteria cell which then led to them figuring out that the virus that they injected into the S cells, were really just injecting DNA. The most interesting part about their experiment is that when RNA was destroyed, the mouse still died and the result was not shanged. -
Rosalind Franklin and Maurice Wilkens
Because the two specialized in crystallography, they were able to crystallize a DNA molecule and were able to examine it with an x-ray. This picture exploded the scientific world and it caught the attention of Watson and Crick. This one picture pushed the two of them into creating the DNA model because it was the one thing that they were missing. The most interesting/ sad part about their research is that Franklin died pretty early and as a result, did not win the nobel peace prize. -
James Watson and Frances Crick
They discovered the double-helix structure of DNA. The structure is a spiral of two DNA strands, each containing a long chain of monomer nucleotides. They made models from scraps of metal connected by wires. They were awarded the Nobel Prize in Chemistry in 1962 for their discovery. -
Linus Pauling
As a scientist, Linus Pauling discovered the alpha helix and the beta sheet in a DNA molecule. The two things that Linus discovered turned out to be the backbone of tens of thousands of proteins. He discovered these things through the use of chemistry which is unusual because most other scientist used different methods to find their conclusions. Because of his research, Watson and Crick were able to make a model on a DNA molecule. -
Matthew Meselson & Franklin Stahl
They discovered the semi-conservative replication of DNA. This is where each strand of DNA serves as a template to make a new, complementary strand. They worked with E. coli bacteria to make their discovery. Their experiment was later named the Meselson-Stahl Experiment. -
Paul Berg
He was an American Biochemist who discovered that DNA from two organisms could be combined through his gene-splicing experiments. The experiments resulted in the first man-made recombinant DNA (rDNA). He worked with with bacterial viruses for his experiments. He went to Penn State for biochemistry and graduated high school at the age of 16. -
Frederick Sanger
They developed the "plus and minus" method for rapid DNA sequencing. DNA was synthesized from templates to generate random sets of DNA molecules. They tested the system by deducing most of the DNA sequence of bacteriophage X174. He received the 1980 Nobel Prize for Chemistry and retired in 1983. -
Kary Mullis
He was an American Biochemist who discovered the DNA polymerase chain reaction. It is a technique that allows a specific stretch of DNA to be copied billions of times in a few hours. The reaction uses four ingredients/reactants: the DNA segment to be copied, two oligonucleotide primers, nucleotides, and the DNA polymerase enzyme. He worked with DNA molecules, bacteria, and viruses. Mullis joined Cetus Corp. in 1979, a California biotechnology firm. -
J. Craig Venter
He discovered a fast way to identify genes. His technique used expressed sequence tags (ESTs), which are segments of DNA in expressed genes to identify unknown genes in other organisms or cells. ESTs were used by Ventor to identify thousands of human genes. The technique was used to identify the gene responsible for a type of colon cancer.
