History of DNA
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Although the scientific community has been aware of DNA for more than 150 years, it is only in the last 60 years that DNA was identified as playing a key role in our genetic information. It wasn't until the mid 1980's that the power of DNA analysis for identification purposes was revealed.
1860's
In the late 1850's an Augustinian monk named Gregor Mendel performed a set of experiments that pointed to the existence of biological elements called genes. In 1865 he presented findings to the Natural History Society of Brunn, calling them the “Experiments in Plant Hybridization.” Unfortunately his work was not appreciated in his own lifetime, however the principles and analytical procedures Medel developed are the basis of what today is the science of Genetics and Inheritance.
Although Mendel was responsible for the foundation of Genetics as a science, the biological elements responsible for the transfer of information from one generation to the other, was discovered by a Swiss biochemist Friedrich Miescher in 1869. Miescher was instrumental in disproving the current theory that all cells were made up of only proteins. While experimenting on pus cells he noted the presence of something that “cannot belong among any of the protein substances known hitherto.” In fact he was able to show that it was not protein at all, being unaffected by the protein-digesting enzyme pepsin.
He also showed that the new substance was derived from the nucleus of the cell alone and consequently named it 'nuclein'. Miescher was soon able to show that nuclein could be obtained from many other cells and was unusual in containing phosphorus in addition to the usual ingredients of organic molecules - carbon, oxygen, nitrogen, and hydrogen.
In 1889 Richard Altmann renamed ‘nuclein’ to ‘Nucleic Acid’ and a few years later in 1893 Albrecht Kossel had succeeded in recognising four nucleic acid bases (nucleotides) Adenine, Thymine, Cytosine and Guanine.
1953
The structure of DNA had been a subject of great debate since 1944 when Avery et al. showed that DNA was responsible for the transference of information form one generation to the next. Many studies had been conducted and much was known about the composition of DNA, however its structure still eluded the scientific community. Then in 1953, James Watson (an American phage geneticist) and Francis Crick (An English physicist) ushered in a new age of biology when they published their paper in the journal Nature suggesting a structure for DNA. That structure — a double helix that can “unzip” to make copies of itself, not only confirmed that it was DNA responsible for genetic inheritance but also proposed a mechanism of action.
1970's
The advances of technology and methodology of DNA analysis in 1970's have made development of tools used for modern DNA testing possible.
1984
The possibility that DNA could be used for human identity and relationship testing had been discussed from the time that DNA was first revealed as the molecule which makes people unique, however, it wasn't until the discovery of the first VNTR (Variable Number Tandem Repeats) probe by Prof. Alec Jeffreys (now Sir Alec) of Leicester University in 1984 when the first practical testing system became available. The first use of DNA testing for human identification anywhere in the world was in the UK as part of a non-criminal case in 1985, Sarbah vs. The Home Office, 1985 (the Ghana immigration case). In this case DNA testing was used to prove the mother-son relationship between Christiana Sarbah and her son Andrew.
2000+
