Home vs legal paternity testing

When deciding on a paternity test, you will invariably be asked whether you require the result for legal purposes or peace of mind purpose.  The actual laboratory procedure for home DNA testing and legal testing does not differ. Both tests involve extraction and amplification of DNA using the same technique and a comparison of DNA profiles (usually comprising a total of 16 genetic markers) extracted from the DNA of the mother, alleged father and child. The difference between home and legal testing takes place prior to the actual processing by the lab – during the sample collection process.  Legal DNA testing carries very strict guidelines and a prescribed set of steps that must be followed in terms of sample collection, documentation and sample custody. This procedure, which will be elaborated upon later in this article, is known as the chain-of-custody and is required by legal entities, typically courts and immigration departments. Home paternity testing, on the other hand, while still as accurate as a legal DNA testing, has no chain of custody.

Understanding the difference in test options

Many leading companies, including International Biosciences, offer both legal as well as peace of mind testing. It is essential that a potential client knows exactly what they will be using their results for prior to purchasing a paternity test. If for you are involved in a court proceeding such as a custody hearing, an immigration appeal, or other legal situations where a judge, court or lawyer is requesting proof of paternity, a legal test is required.  A paternity test can:

  • Be used to establish a biological relationship between an alleged father and a child in order to secure custody, visitation rights, or provide for child support
  • Prove a biological relationship in an immigration case in order to assist with the naturalization of a child to a country where his or her father lives
  • Release a man from any responsibility financial or otherwise when he is excluded – proven not to have a biological relationship – in a given paternity test

Home paternity testing

In situations where a person needs a paternity test that will be for information purposes only (for peace of mind), and not used in a court setting, a home paternity test will suffice.  These types of tests can, for example, alleviate doubts that a mother may have concerning the actual biological father of her child.  Home tests can also be used by fathers to get absolute certainty that they are in fact the father of a child or, by extension, to provide them with scientific proof they are not.  While a home test will not be admissible in court, it could be a quick and cost effective first step in establishing paternity.  For example, prior to going through the necessary process of securing legal representation, suing, etc., a person may wish to perform an affordable and accurate home test before investing in moving forward.  The test is not legally binding but can be the foundation on which legal action is begun.  With a home paternity test, interested parties will be responsible for collecting their own DNA samples using a home sample collection kit. Once they have collected their samples (typically using mouth swabs), they will need to fill out some basic registration and consent forms and send everything off for testing.

Legal paternity testing

The key to understanding legal paternity testing lies wholly in the sample collection and chain-of-custody procedure.  A typical legally binding analysis will involve the addition of a 3rd party that is neutral to the test – this person is in charge of collecting the samples and verifying the identity of all test participants.  This person, known as the Sampler, will not only be responsible for collecting the DNA samples themselves from every test participants, but will also be the only person handling the samples, sealing these into the appropriate envelopes with the necessary consent forms and documentation and sending them off for laboratory analysis.  Results of a legal test are issued by email and also by hard copy. The hard copy is a notarised copy, which means it is signed by a laboratory notary. The notarised copy can be presented in court as proof of paternity.

Motherless paternity testing

Paternity tests can be carried with or without the mother’s sample. Generally legal tests are always carried out with the mother’s DNA sample and home tests sometimes include the mother’s sample whilst in other times they do not. It does baffle people when DNA testing companies offer paternity testing with the mother’s sample – it seems somewhat strange to include the sample of the mother when one’s aim is simply to find out whether there is a biological relationship between the father and child. However, in terms of laboratory analysis, having the mother’s sample will allow for a more accurate result since once in the laboratory, the mother’s share of genetic inheritance can be neatly excluded from the profile of the child leaving just the paternally inherited DNA to analyse.

Karl M McDonald is a freelance writer specializing in the field of genetics and DNA testing.