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Fredrick Griffith
Fredrick Griffith injected a mouse with a harmful bacteria and the mouse died. He then injected a mouse with a denatured bacteria and the mouse lived. Lastly, Griffith injected a mouse with both harmful bacteria and denatured bacteria, and the mouse died. His experiments showed was it called "transformation" which is the process in which genetic information passes from one bateria to another. -
Alfred Hershey and Martha Chase
These two scientists furthered Griffith's research by researching ecoli and bacterial phages. Bacterial phages latch onto a cell and inject their substances, protiens and DNA. The scientists tagged Phosphorus 32, which detects the DNA, and Sulfur 35, which detects the protiens. The scientists then detected Phosphorus 32 inside of the cell which would mean that the bacterial phage injected DNA into the cell. -
Erwin Chargoff
Erwin Chargoff studied the structure of DNA and realized a pattern in thymine, guanine, guanine, and adenine. Chargoff realized that the amount and size of adenine equaled that of thymine, and that the amount and size of guanine equaled that of cytosine to form the double helix. -
Oswald Avery, Maclyn McCarty, and Colin MacLeod
Avery, McCarty, and MacLeod continued Fredrick Griffith's reasearch on inheritence, as they called DNA at that point in time. The group destroyed carbohydrates to see if a "transformation" occured even without the carbohydrates; he transformation still occured. Next, they destroyed DNA and saw that the transformation did not occur without the DNA, therefore showing that DNA is the cause of transformation. (Oswald Avery is the man pictured). -
Francis Crick and James Watson
Francis Crick and James Watson discovered the double helix in DNA. The men's experiments included mostly models and observation of other scientists' work as opposed to lab work. The men called the strands "anti-parallel" and that idea that the strands did not line up is what took the men the majority of their research time to discover. -
Rosalind Franklin
Rosalind Franklin studied the structure of DNA using x-ray crystalography.The man who Franklin worked in the lab with sold her diagrams to Francis Crick and James Watson who both beat her to publication. Throughout her life, Franklin was not given much credit for her ideas, and it was after she died young of cancer that she was recognized for her discoveries. -
Matthew Meselson and Franklin Stahl
Matthew Meselson and Franklin Stahl proved that each one strand of DNA produced two new strands of DNA. The men put nitrogen in ecoli strands and discovered with that that original DNA makes itself a template and replicates itself to make new DNA (the DNA is known as being "semi-conservative").
