BY SOLA OGUNDIPE –
Vanguard Media LTD has commenced a process of conducting DNA test on Precious Donatus Ogbonna and the seven babies she allegedly had within eleven months.
A popular laboratory has been contracted and money ear-marked for the test that would put an end to all arguments over the truth of the woman’s claims. DNA is the most reliable and assured way of resolving any question mark looming over a child’s paternity or maternity. That is the only way the issue of an individual’s parentage, identity or family lineage can be established beyond reasonable doubt.
Over the years, the DNA blood test has emerged as the most infallible way of convincingly answering the question of family relationship. DNA testing is a powerful tool for identification and with today’s technology, can identify individuals with almost 100 percent certainty.
Often referred to as DNA blood testing, parentage testing or DNA fingerprinting, the DNA blood test is utilised to identify and evaluate the genetic information-called DNA (deoxyribonucleic acid)-in a person’s cells. It is called a “fingerprint” because it is very unlikely that any two people would have exactly the same DNA information, in the same way that it is very unlikely that any two people would have exactly the same physical fingerprint. The test is used to determine whether a family relationship exists between two people, to identify organisms causing a disease, and to solve crimes.
Nowadays, paternity testing and other DNA tests rely heavily on DNA’s structure and function. Since DNA’s structure was discovered in 1953, numerous techniques have been developed to use this knowledge to learn more about how living things function and solve human problems.
With the introduction of DNA testing in the late 1970s and 1980s, scientists have appreciated the powerful tool this process could be for identification and determination of biological relationships. Thanks to the advent of DNA testing, identities of individuals in relation to their relatives can now be determined with exceptional accuracy and conclusiveness.
That DNA testing has revolutionised the paternity and family relationship testing industry is no surprise. It is far more accurate than other forms of testing and therefore immensely popular amongst people that are trying to establish parental lineage. DNA blood testing is done in laboratories under strict laboratory conditions so there is minimal chances of the wrong evaluation been given.
A drop of blood or root of hair is good enough to confirm the result, because blood and hair contain enough DNA for testing. Essentially, semen, hair, or skin scrapings are often used in criminal investigations. A person who has DNA fingerprinting done voluntarily usually provides a sample of blood taken from a vein. DNA testing also can be done on cells obtained by a simple mouthwash or a swab of the cheeks inside the mouth, but these methods are not recommended. DNA is extracted from the white blood cells after the blood sample is put into a centrifuge and the blood is split into different components. DNA blood testing is more invasive than other methods of DNA testing because a needle is used to extract blood as opposed to a swab that takes skin samples of DNA.
Why It Is Done
The most common use of DNA fingerprinting is to solve crimes (forensic science). Blood, semen, skin, or other tissue left at the scene of a crime can be analysed to help prove whether the suspect was or was not present at the crime scene. But DNA fingerprinting is done to determine who a person’s parents or siblings are. The test also may be used to confirm paternal or maternal identity of children as well as to identify badly decomposed or dismembered bodies.
How it is done
DNA can be collected from dried blood, skin, saliva, hair, urine, and semen. Bone and teeth samples are used when a body is badly decomposed, but DNA that is used to establish paternity or maternity is collected from a blood sample. The health professional drawing blood will wrap an elastic band around the upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
If a DNA blood test is done on a baby, a heel stick will be done instead of a blood draw from a vein. For a heel stick blood sample, several drops of blood are collected from the heel of the baby. The skin of the heel is cleaned with alcohol and then pricked with a small, sterile lancet. Several drops of blood are collected inside circles on a specially prepared piece of paper. When enough blood has been collected, a gauze pad or cotton ball is placed over the puncture site. Pressure is applied to the puncture site briefly and then a small bandage is usually placed over it.
DNA is generally painless and free of risk if carried out by a professional in an approved health centre. Apart from a brief sting or a pinch when the lancet pricks the skin, there is very little or no discomfort. Collection of DNA from saliva, urine, or semen does not cause discomfort or risk. DNA samples can determine or establish paternity. Tissue samples from two people can also be compared to determine how likely they are to be blood relatives.
How it works
DNA is inherited from both biological parents. It is found in all cells of the body and composed of four different molecules—adenine (A), thymine (T), cytosine (C), and guanine (G). Like the letters of an alphabet, these four molecules are arranged in strings of specific sequences that spell out instructions for our body’s everyday functions. DNA contains information that dictates our physical characteristics, such as facial features, height, and even health.
During conception, the father’s sperm cell and the mother’s egg cell, each containing half the amount of DNA found in other body cells, meet and fuse to form a fertilized egg, called a zygote. The zygote contains a complete set of DNA molecules, a unique combination of DNA from both parents. This zygote divides and multiplies into an embryo and later, a full human being.
At each stage of development, all the cells forming the body contain the same DNA—half from the father and half from the mother. It is this fact that enables scientists to use a variety of sampling methods for DNA testing. We can take samples at virtually any stage of development and from any part of the body—and still obtain the same results, because these samples contain the same DNA. The DNA test works because each person has a unique genetic profile that reflects this inheritance.
Special locations (called loci) in human DNA display predictable inheritance patterns that could be used to determine biological relationship.. These locations contain specific DNA sequences, called markers, that forensic and DNA scientists use as identifying marks for individuals. In a routine DNA paternity test, the markers used are Short Tandem Repeats (STRs), short pieces of DNA that occur in different repeat patterns among individuals.
Each person’s DNA contains two copies of these markers—one copy inherited from the father and one from the mother. Within a population, the markers at each person’s DNA location could differ in length and sometimes sequence, depending on the markers inherited from the parents.
The combination of marker sizes found in each person represents his/her genetic profile. DDC examines a minimum of 16 STR markers to create a genetic profile for each tested person in a paternity, identity or family relationship test.
Under the right conditions, DNA test is 99.99 percent accurate and the results can be used in a court of law. Another test that can help determine paternity or genealogical relationship includes genetic testing. However, sample size is the most telling factor. The possibility of inaccurate test results increases if a very small sample of DNA is available for testing. The chance that the DNA will be mixed up with some other DNA is also higher with a smaller sample. Anyone who has had a blood transfusion within the past three months may not be eligible for DNA testing.
DNA blood testing results are used commonly in the search for truth and often justice. For parental and ancestry confirmation, DNA testing is fast, easy and accurate and therefore is not a problem to gather the required information and provide results for the question that needs an answer.
DNA testing is a powerful tool for identification. With today’s technology, DNA tests can now identify individuals with almost 100% certainty.
Identification has not always been this conclusive. Before DNA tests, the science community used other biological tools to identify people and determine relationships. These techniques, which included blood typing, serological testing, and HLA testing, were useful for other uses (such as matching blood and tissue donors with recipients and reducing the rejection rate for transplant patients), but they were not effective for identification and determining relationships.