Human body is made up of innumerable cells and every cell has a nucleus containing valuable genetic information. DNA or deoxyribonucleic acid, contains the genetic instructions that are used for the development of all living organisms. Genes store this information for a long time in the form of codes and are considered as units of heredity.
DNA is made up of millions of base pairs of nucleotides and the sequence in which they are present in the particular strand determines the characteristics of the person.
The DNA sequence is unique to each individual and represents a genetic blueprint. This property of uniqueness of the DNA sequences makes it an important tool in the identification of individuals by a process known as DNA profiling.
Also referred to as DNA fingerprinting or DNA typing, it is a process of identifying an individual on the basis of their respective DNA profiles. It is one of the techniques used by law enforcement to identify criminals or to eliminate suspects.
Typical cases involve the comparison of the DNA sample of a person with the existing DNA samples, or creating a new DNA profile for the person by assigning a computerized numeric value or bar code. This technique analyzes the DNA samples for variable number tandem repeats (VNTR).
DNA Fingerprinting Process
DNA profiling is mainly used as a forensic tool. However, this technique of identification of individuals is also used in genealogy. The process involves collection of a sample of an individual DNA and matching it with the reference samples. The sample is usually collected using a buccal swab as it has minimum chances of contamination.
Other methods of collection of sample include samples of blood, saliva, semen, or tissue. These samples are then analyzed by different methods to create the individuals unique DNA profile. This profile is then compared against other reference samples to find a genetic match. DNA samples taken from the crime scenes help in identification of criminals.
Pros and Cons of Profiling of the DNA
DNA profiling helps elimination of innocent suspects and sets them free. It is a means of rapid identification with a high level of certainty. This can be a boon for those who are falsely or wrongly accused.
This technique plays an important role in solving the issues related to paternity and other family-related matters. It helps in the identification of other family members and also for establishing twin zygosity. Moreover, the technique involved is less invasive than taking a blood sample and is extremely reliable when done properly.
Although DNA profiling has proved to be an excellent forensic tool, genetic profiling is still a debated issue. The main concern is about privacy. Some people consider DNA sampling as a violation of an individual's right to privacy and other civil liberties.
There could be several problems associated with the access to this vital genetic information, like, in some cases, health insurers may deny coverage or claims, or employers could avoid hiring people with certain genetic traits or genetic disorders and diseases.
Another major concern is of public humility and discrimination against people who are closely associated with those in trouble with the law. Accuracy is a major factor that rules the results of DNA testing and a simple mistake in the analysis may lead to wrongful conviction.
DNA testing during pregnancy has become very common these days, to establish paternity of the unborn child. However, this technique has serious risks for the child as well as mother and hence it is advisable to go for postnatal DNA testing.