In trying to establish the DNA of a child, different labs use different methods depending on why you need the DNA paternity test done, and if you will be using it as a legal document.
The timing of the DNA paternity test is also another consideration. It is possible to do a DNA paternity test even before the child is born, although there are some medical issues about invasive techniques used.
For instance, for a pre-natal DNA paternity test, the doctor will have to conduct an amniocentesis which requires a needle to be inserted into the uterus to collect amniotic fluid. The problem with this kind of testing is possible injury to the fetus, and cramping and bleeding for the pregnant woman. Both of these conditions could be fatal for the unborn child.
Photo: DNA Diagnostics Center
At any rate, here are some of the other methods used in DNA paternity tests
Postnatal DNA paternity tests are a better alternative to the invasive pre-natal paternity test. It can be done immediately after birth using the umbilical cord, hair, a saliva swab, or even a skin or blood sample. There is no risk to either the mother or the baby at this point, and the samples are very viable.
The CVS or Chronic Villus Sampling is another method used in testing paternity through DNA. It is done when the child is still unborn. Although also invasive, it does not involve a needle into the uterus. Rather a tube is inserted into the woman’s vagina and chorionic villi which is a substance that lines the uterus is collected.
Photo: The Internet Encyclopedia of Science
Method 3 and Method 4
These are the two most commonly preferred methods of testing DNA for paternity issues. It involves taking a sample of the saliva through the mouth with a swab. This method is known as
Polymer Chain Reaction or PCR. The sample is then defragmented through a process known as gel electrophoresis. The fragments of DNA are then analyzed and compared with each other.
The other commonly used method is the Restriction Fragment Length Polymorphism or RFLP. The main difference between the PCR method and the RFLP method is the use of enzymes with the latter method. The fragments are then organized according to size before comparing with the other DNA samples.
Photo: Swiss DNA Bank
The home DNA paternity test is usually the cheapest and most convenient. However, it is also the most suspect, mainly because of identification issues. Thus, this method is rarely, if ever, accepted in a legal battle.
Photo: Impact Lab