What Are DNA Paternity Tests?

The process that is used to identify and establish if a man is in fact the biological father of a child, or to prove otherwise, is known as DNA Paternity testing. This test can be done as a postnatal test or as a prenatal test to establish paternity. Due to the risks involved in the prenatal testing process, it is recommended (and preferred) that the postnatal process of DNA testing be used.

DNA - Definition, Structures and Paternity determination

Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions used in the reproduction, development and functioning of all known living organisms. The main role of DNA molecules is the long-term storage of information that forms the basis of heredity, the development of personality traits, and physical characteristics such as hair color, adult height, etc.

The structure of human DNA resembles that of a double helix or a twisted ladder. There are four bases that comprise the two sides of the ladder. These bases are connected by hydrogen bonds which act as the "rungs". The arrangement of the molecules is called the DNA Sequence and contains the detailed list of physical characteristics found within the genes. Each person's DNA sequence is unique.

To extract DNA samples, chemical agents are used from which a DNA profile is created. This involves a complex process that identifies the locations, or loci, on the DNA helix. The testing is continued by using a molecular replication to create "maps" of the loci. This is referred to as DNA profiling.

Paternity is established if during testing half of the child's loci matches with that of the alleged father. If three or more loci do not match then a paternity cannot be established with the alleged father and further testing may be done depending on specific markers that do no match to arrive at conclusive and accurate results.

Various Types of DNA Paternity Testing Processes

The Buccal Swab and Pin Prick are the two most widely used postnatal methods of DNA testing.

Buccal Swab Process

The Buccal (cheek) swab process of testing is totally painless as the samples are collected by swabbing coated cottons on the inside of the cheek. The DNA sticks to the swabs' ends when rubbed against the cheeks for later extraction and processing.

"Pin Prick" Process

A small lancet is used to prick the finger and collect a small amount of blood on a collection card. This collection of blood will then be used for DNA testing. While testing children below the age of 8 it is highly recommended that a qualified doctor does the blood sample collection or instead use the Buccal swab process.

In cases where the DNA of the alleged father is not available due to him being missing or deceased, it will still be possible to establish paternity by testing the father's parents for a match. The samples of the father's parents will be collected and tested.