Discovered by : Friedrich Miescher
Discovered in year : 1869
DNA stands for DeoxyrioNucleic Acid. DNA is a nucleic acid which contains the genetic instructions used in the development and functioning of all known living organisms and some viruses as well. Deoxyribonucleic Acid is an extremely long macromolecule that is the main component of chromosomes and is the material that transfers genetic characteristics in all life forms. It is constructed of two nucleotide strands coiled around each other in a ladder like arrangement with the side pieces composed of alternating phosphate and deoxyribose units and the rungs composed of the purine and pyrimidine bases adenine, guanine, cytosine, and thymine.
DNA was first discovered, isolated, analysed and recognized as a unique macromolecule by Friedrich Miescher in 1869. Friedrich Mischer was an eminent physiological chemist from Switzerland. He worked in the laboratory of physiological chemistry of eminent scientist Felix Hoppe-Seyler. At the time of the discovery he was 25 years old and had not long graduated from his studies. He discovered it while examining pus-ridden bandages used for surgical wounds very closely and observed a strange microscopic substance in the nucleus of cells. He called it 'Nuclein' because it was found in the nucleus. Though he discovered it, he did not know if it was the hereditary material and he also did not call it DNA.
Development in the Findings of DNA
In 1919, Phoebus Levene identified the base, sugar and phosphate nucleotide unit in the structure. Further, in 1937, William Astbury produced the first X-ray diffraction patterns that proved that DNA had a regular structure.
In 1928, Frederick Griffith performed experiments to prove that DNA carried genetic information. Thereafter, Oswald Avery along with his co-workers identified DNA as the transforming principle in the year 1943. The role of DNA in heredity was confirmed in 1952, when Alfred Hershey and Martha Chase showed that DNA is the genetic material of the T2 phage. Finally in 1953, James D. Watson and Francis Crick suggested the first accurate model of DNA structure. It was the Meselson-Stahl experiment in1958, which led to the final confirmation of the replication mechanism that was implied by the double-helical structure.
Role of DNA in the Improvement Of Human Life
- DNA is used for Forensic Identification for various purposes like criminal investigations(DNA fingerprinting ), scientific studies etc.
- Genes are used for developing high yielding crops
- A proper understanding of DNA has helped in development cure for various diseases
- New organs can be produced with the help of DNA knowledge
- The Human Genome Project has uncovered an enormous amount of information about DNA, the building blocks that make us who we are. This knowledge can be used for diverse applications such as identifying genetic susceptibility to medical conditions, diagnosis of disease, relationship testing and forensic science.
- DNA technology is helping in the improvement of animal breeds.
