Importance of DNA technology
The Full form of DNA is Deoxyribonucleic acid. Lately, DNA technology has greatly and rapidly advanced and because of that, it has been useful in many fields of study and in practical life. From determining paternity to catching criminals, DNA tests have various purposes and have been an integral part of law enforcement agencies and crime investigations. Even archeologists find DNA, a useful source of information. They are now using DNA tests to keep a systematic record of genetic codes and progression of life on earth which dates back to centuries. This helps in making a DNA database which can be used for reference and comparison purposes later.
Types of DNA Test
There are 3 types of DNA test are available each of which looks at a different part of the genome and useful for different types of genealogical research. They are, autosomal, mitochondrial and Y. Generally, these DNA tests do not give information about medical conditions or diseases. With the process of profiling the DNA of living organisms, scientists have proved evolution and genetic mutation and have been able to answer questions on the origins of species. A paternity test is the most definitive way of confirming a child’s paternity and legitimacy. For social and legal reasons paternity tests have helped to protect the rights of the child and prove legitimacy and illegitimacy. Recently sibling and grandparent tests are also evolving to help people find their long lost relatives and fill the gaps in the family tree. Because of this growing interest in family trees a DNA test has highly been used to help people find out about their genetic ancestors. The Y chromosome which is found in males is likely to remain unchanged from different generation to generation its analysis can be used to set up ancestral lines and complete the family lineage.
People are also using DNA test to establish their ancestor’s ethnic background which can be dated hundreds and thousands of years back. It has also made great breakthrough in the field of diagnosis. With the help of prenatal genetic tests doctors can now determine whether the unborn fetus will have health problems or will be born healthy. Doctors have also been using DNA tests to determine the probability of risk of certain genetic diseases like prostate cancer. They can now be identified as a high risk disease and ensure regular checkups which will lead to better results as the cancer was diagnosed at an earlier stage. DNA tests, phenotyping and other such methods are now being widely used in criminal investigations. In cases of repeat offenders police can store DNA profiles and compare them with the samples of other unsolved crimes and find a possible match a glaring example of which is the case of the infamous serial killer of America, Gary Ridgeway. He evaded the investigators for a span of 20 years during which he killed around 50 women. His DNA samples taken from his earlier victims proved to be the only physical evidence that helped to convict him. There have been cases where individuals who were previously convicted of crimes being exonerated because of new evidence submitted through DNA testing. Many cases that were unsolved and closed were successfully opened and investigated with the help of DNA tests.
The extent of DNA technology is so wide that it has reached space. In space research, scientists are also conducting DNA tests on new species and unidentified articles and compounds from outer space. This can be a crucial link in establishing origins and connections to existing life forms and other living organisms. DNA test provides perfect identity and is the most admissible evidence in any law of court. They are persuasive evidence and can help a case lead. The admissibility of the DNA evidence before the court will always depend on its accuracy and collection, preservation and documentation which can satisfy the court that the evidence which has been put in front it is reliable and will help achieve justice to those who are seeking. There is no specific legislation or guidelines which are present in India which can provide specific guidelines or instructions to the investigating agencies and the court.
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The procedure for collecting DNA samples
DNA testing is a simple process that starts at a collection site which is the first procedure and it is painless and hassle free. The parties are required to submit government approved photo identification which can be something like driver’s license. The collector will complete the process and collect the DNA samples by using oral swabs and take a photograph of all the tested parties. If the participants are minors the legal guardian or parent must be available to sign on their behalf. If the mother is a minor then she can sign for her baby but must have a legal guardian or parent to sign for her if she is to be tested and sign on her behalf. Samples for a DNA test like a paternity test are collected using simple buccal swabs that are similar to a cotton-tipped swab but they are made of a special material called Dacron. The swab is rubbed against the inside of the cheek of the test person taking the test and the loose cheek cells get collected to the swab. Unlike regular cotton swabs Dacron has a more consistent surface for better sample collection and DNA extraction. The sample collector then sends the swabs to the respective laboratory in a sealed tamper-evident package so that the samples do not get tampered with. Each sample will be recorded into the database for further reference. Once all the samples have been received and collected in the lab the DNA testing begins and they have the following five steps:
- Samples from each person doing the test are divided into two. After this two independent laboratory teams will take the samples through the DNA testing process so that two separate and independent tests are completed by two different Scientists and makes it more reliable.
- DNA is extracted from the buccal swabs from the cheek mostly and purified.
- The extracted DNA is then added to a special chemical mix for the Polymerase Chain Reaction (PCR) which is a process that targets at least 16 specific locations in the DNA which is called loci and makes billions of copies of each location in the DNA.
- The products of PCR are analyzed to create a DNA profile and a genetic equivalent of a fingerprint for each tested individual.
- Each kind of test differs depending on the purpose. For Paternity Testing the child’s DNA profile will be compared with the alleged father’s and statistical analysis is performed to determine the probability of paternity and legitimacy. If it’s a 0% probability represents an “exclusion” which means that the alleged father is not the biological father of the child subject to the test and at least a 99.9% probability represents an “inclusion” which means that the alleged father is the biological father. The technology is so advanced that testing can also be done if the alleged Father is not available for testing.