DNA Fingerprinting


‘DNA finger printing’ is useful in a crime scene or establishing paternity or archaeology or to put it in a nutshell, let us say it is used in various fields of biology. Most of us have heard about it many a times especially through newspapers. This DNA is a part of your own body. And having knowledge about what you possess is very important and so does about DNA and it’s fingerprinting.

Basically it is a technique which is used to distinguish folks of the same genus by just collecting the samples of their DNA. I wonder how come a single DNA ( deoxy-ribonucleic acid ) can do so many wonders. It’s wonderful!

What is a DNA?

Well, DNA is a nucleic acid that contains the genetic instructions (the characteristic features of human genome) used in the development and functioning of all known living organisms and some viruses. These instructions act as preservatives that carry different characteristics of human body from one specie to another. So basically, the main role of DNA molecules is the long-term storage of such information. As you would know, the word ‘gene’ used in common language, is the heredity material and a part of DNA. These carry information from one generation to another, from the parents to the offsprings. Therefore, with the help of these we can get a clue of one’s DNA or paternity. These strands of DNA, chromosomes, are in pairs, precisely 23 pairs; 46 in total. Genes are present all over these strands and help in the process of heredity and evolution.

For example, when a murder takes place, evidences are taken into account. These include the weapons of destruction, complete observation of the crime scene, statements of the witnesses and victims. With this arrives the preservation of the found fingerprints on the various possessions of the house.

This is how it works –

DNA are separated from the bulk genomic DNA of the body which is the major DNA. These DNA are in form of double strands that is in shape of a double helical structure. After separating them from the human body, they are arranged into columns or long vertical lanes, one in each lane. Using a gel, it is then cut into small pieces in any way we want. These sequences of DNA are repeated in form of VNTRS (Variable Number of Tandem Repeats) in our body. The number of these sequences vary in different people and can therefore be used as a fingerprint which varies from one person to the other. The number can vary from 4 to 7 repeats or more. If a lot of DNA pieces are analyzed, a fingerprint comprising many fragments emerges. This is a lot of DNA fragments altogether. These fragments are then spread on a gel and it is recorded to whom of the prime suspects the DNA matches. With this, one can easily define who could be the major suspect and to whom the recorded finger prints match.

Apart from all these, DNA fingerprints have got various other applications. Likewise, it helps in biological classification, that is to show evolutionary variations and relationships on the molecular level. This means that it deals with evolution, the origin of various species. Doesn’t that sound interesting? We all human beings share the same history of evolution with other mammals, land living animals. It is just that on differentiation and maturity, we have originated as human beings with unparalled senses. It is also used in tiny pieces of preserved tissues of extinct animals. It seems to be an easy process and undoubtedly it is. Just a fragment of DNA and there you are with the prime suspect in your hands. The increasing efficacy of the DNA fingerprinting process means that it is being considered by the CDFD which is the Centre for DNA Fingerprinting and Diagnostics as a viable tool in fighting terrorism in India.¬†Seems just like some wonderful invention of science and believe me it is. Therefore knowledge about anything especially such knowledge is important and being different. Science has done so many wonders and such ones on the angstrom levels are appreciable and miraculous. Hats off to Dr. Alec Jeffreys.

Shelly Mahajan

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