Although the public knows much more than they did about DNA paternity testing, there is still a lot of misunderstanding over what can and cannot be done, and there is still a lot of education needed before they understand the technique.

Because of this, it is important that you consider these questions that are often asked by people about to take such DNA tests.

1.  Is There any Better Way of Proving Maternity or Paternity?

No, DNA comparison is the most accurate known method and can prove to within 99.9% plus, that a person is the biological parent, and 100% that they are not. The previous blood type screening was not nearly so accurate, and could not in reality prove parentage.

2.  How Does a Legal DNA Paternity Test Differ from One Done at Home?

A home paternity test has no legal weight, and is done only if you want peace of mind (in fact it is also called the ‘Peace of Mind Test’) regarding paternity. It is sometimes referred to as the ‘curiosity test’.

What you do is to order a testing kit which is sent to your home together with instructions, labels and a consent form.  Following the instructions you will take a sample from inside your cheek – the cheek cells and saliva are tested. You then post that away to the lab for testing and await the results that have no legal standing.

The sample for the legal DNA test has to be taken by an accredited third party, such as a doctor nurse. It is important that the provider of the sample is properly identified, and that there is a strict procedure of custody of the sample until it has been tested. This is all to make sure that the right person is being tested so there is no identification error. This makes no difference to the test result, just that the legal requirements regarding proper identification of the sample are carried out, so that the result is legally binding.

3.  How Can I Make Sure I Get a Good Laboratory?

The best way to check on the credentials of a DNA testing laboratory is to look for the ISO 17025 accreditation and that it has AABB Accredited Parentage Testing Facilities. Checking accreditation is the best way, and you must also ensure that all standard 21 loci, or DNA regions, are fully profiled. The lab should not just provide a positive or negative result, but give the statistical probability of paternity of the subject.

4.  Is a Sample From the Mother Necessary for a Paternity Test?

It’s not essential, although in certain circumstances such as gene mutation, a mother’s sample will help provide more accurate results. If a sample is available you should include it, and in the UK you will need the consent of at least one of the recognized parents to take a sample from the child. Unless you are certain you have that authority, you might have to include the mother.

5.  Is it only Oral Swabs That Can be Used as Samples for a DNA Test?

No – anything containing DNA can be used. Common sources are blood, saliva, semen and hairs, and any articles containing these such as cigarette butts and tissues. An oral swab is preferred since it requires least preparation, but if the subject cannot be present, or is unwilling to participate, thee other options can be used.