Dr Reena Gupta and Dr Vikas Mahajan
DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA). The information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same in all people. The order, or sequence, of these bases determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences. DNA fingerprinting is a way of identifying a specific individual, rather than simply identifying a species or some particular trait. It is also known as genetic fingerprinting or DNA profiling by Sir Alec Jeffreys in 1985, inventor, of this technology. DNA fingerprinting has a number of applications ranging from criminal investigations to paternity disputes. DNA samples may be collected from a number of sources including hair, blood, saliva, semen, skin, and other fluids or tissues. There are many advantages to DNA fingerprinting Benefits of DNA Fingerprinting:
The most widely known use for DNA fingerprinting is in the field of forensics, samples of DNA do sometimes play a large part in the conviction or exoneration of individuals under suspicion of having committed a crime. With DNA fingerprinting we can find our birth parents if we were adopted. There is a strong similarity shown between genetic fingerprints of parents and children. This is a benefit because a child’s genetic fingerprint is made up of half the father’s genetic information and half of the mother’s information. This means that the bands of a child’s genetic fingerprint will match the bands on both of their parents, making it possible to establish paternity and maternity tests. Advances in DNA fingerprinting have also led to benefits in both agriculture and animal husbandry. Much like the results from paternity tests in humans, DNA fingerprinting can be used to identify the origins of a particular plant or animal. In agriculture this is beneficial because it allows for the proper identification of seeds or plant samples to verify that they are from the particular desired species. DNA fingerprinting is also used to identify the origins of some of the herbs and plants used in alternative medicine. Using DNA fingerprinting, the exact origins and ancestry of an animal can be determined. As techniques advance and more is known about the genome, this could even lead to predictions of sickness and other factors that would further determine the animal’s value.
Limitations of DNA Fingerprinting
One of the main problems with the process of DNA fingerprinting is that the sample can be easily ruined. The tiniest pieces of genetic junk can contaminate DNA samples, causing them to be useless but this problem can be solved by using the newer technique called PCR. Another limitation og fingerprinting is that the procedure is so complex and hard to read the DNA patterns, that sometimes the juror finds the evidence almost invisible. Although DNA Fingerprinting is a highly advanced process, there are still some things that it is unable to do. In dogs for example, a fingerprint does not make it possible to determine if the animal is a carrier of a disease causing allele. Also, a DNA fingerprint is unable to show a crossbreed in animals. This is because second or third generation crosses cannot be seen by working backwards in a pedigree. It may soon become possible to discover the crossbreed of dogs, although right now this is not possible. Analysis may be expensive and can add to an already hefty defense tab.
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