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Miescher
his aim being to elucidate the building blocks of life. he first investigated the proteins in these cells.During these experiments, he noticed a substance with unexpected properties that did not match those of proteins.He had obtained the first crude purification of DNA. He further investigated the properties and composition of this enigmatic substance and showed that it fundamentally differed from proteins. Due to its occurrence in the cells' nuclei, he termed the novel substance “nuclein" -
Griffith
Griffith's experiment showed that bacteria were capable of transferring their genetic information by a process that he called transformation. -
Avery
By the 1940s, genes were understood as discrete units of heredity, which also generate the enzymes that control metabolic functions. Contemporary wisdom suggested that genes were proteins. But in 1944, experiments by Oswald T. Avery showed that a nucleic acid, deoxyribonucleic acid (DNA), known to be ubiquitous in organisms, was the chemical basis for specific and apparently heritable transformations in bacteria. -
Chargaff
Erwin Chargaff’s research paved the way for the discoveries of DNA’s structure and its method of replication. His observation that DNA varies from species to species made it highly credible that DNA was genetic material. His identification of 1:1 ratios in DNA’s bases allowed James Watson and Francis Crick to see how these bases slotted into the double helix and how DNA could act as a template for copies of itself. -
The start of a new discovery branch
Maurice Wilkins (1916- ), Rosalind Franklin (1920-1957), Francis H. C. Crick (1916- ) of Britain and James D. Watson (1928- ) of the U.S. discover chemical structure of DNA, starting a new branch of science--molecular biology. -
Hershey and chase
The Hershey–Chase experiments were a series of experiments conducted in 1952 by Alfred Hershey and Martha Chase that helped to confirm that DNA is genetic material. While DNA had been known to biologists since 1869, many scientists still assumed at the time that proteins carried the information for inheritance because DNA appeared simpler than proteins. -
Franklin & Wilkins
Wilkins began using optical spectroscopy to study DNA in the late 1940s. In 1950 he and Gosling obtained the first clearly crystalline X-ray diffraction patterns from DNA fibres. Alec Stokes suggested that the patterns indicated that DNA was helical in structure.
The discovery of the structure of DNA in 1953 revealed the physical and chemical basis of how characteristics are passed down through the generations and how they are expressed in individual organisms. -
Watson and crick
In the early 1950s, Watson and Crick were only two of many scientists working on figuring out the structure of DNA.. On the morning of February 28, they determined that the structure of DNA was a double-helix polymer, or a spiral of two DNA strands, each containing a long chain of monomer nucleotides, wound around each other. According to their findings, DNA replicated itself by separating into individual strands, each of which became the template for a new double helix. -
Kornberg and the DNA tube
Arthur Kornberg (1918- ) of the U.S. produced DNA in a test tube.
