Search results
Results from the WOW.Com Content Network
1977: DNA is sequenced for the first time by Fred Sanger, Walter Gilbert, and Allan Maxam working independently. Sanger's lab sequence the entire genome of bacteriophage Φ-X174. [49] [50] [51] In the late 1970s: nonisotopic methods of nucleic acid labeling were developed.
In the 1940s and early 1950s, experiments pointed to DNA as the portion of chromosomes (and perhaps other nucleoproteins) that held genes. A focus on new model organisms such as viruses and bacteria, along with the discovery of the double helical structure of DNA in 1953, marked the transition to the era of molecular genetics.
After that, E. coli cells with only 15 N in their DNA were transferred to a 14 N medium and were allowed to divide; the progress of cell division was monitored by microscopic cell counts and by colony assay. DNA was extracted periodically and was compared to pure 14 N DNA and 15 N DNA. After one replication, the DNA was found to have ...
Working in the 19th century, biochemists initially isolated DNA and RNA (mixed together) from cell nuclei. They were relatively quick to appreciate the polymeric nature of their "nucleic acid" isolates, but realized only later that nucleotides were of two types—one containing ribose and the other deoxyribose. It was this subsequent discovery ...
1997 – British scientists, led by Ian Wilmut from the Roslin Institute, report cloning Dolly the sheep using DNA from two adult sheep cells. 1999 – Discovery of the gene responsible for developing cystic fibrosis. 2000 – Completion of a "rough draft" of the human genome in the Human Genome Project.
The cells were filtered, and since centrifuges were not available at the time, the cells were allowed to settle to the bottom of a beaker. He then tried to isolate the nuclei free of cytoplasm . Miescher subjected the purified nuclei to an alkaline extraction followed by acidification, resulting in the formation of a precipitate that he called ...
In 1979 Cetus Corporation hired Kary Mullis to synthesize oligonucleotides for various research and development projects throughout the company. [14] These oligos were used as probes for screening cloned genes, as primers for DNA sequencing and cDNA synthesis, and as building blocks for gene construction.
Rosalind Franklin joined King's College London in January 1951 to work on the crystallography of DNA. By the end of that year, she established two important facts: one is that phosphate groups, which are the molecular backbone for the nucleotide chains, lie on the outside (it was a general consensus at the time that they were at the inside); and the other is that DNA exists in two forms, a ...