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Paternity test (PT)

Paternity test. A clear answer from a cheek swab.

A DNA comparison between a child and a possible father, a mother, or a sibling. Samples are taken at the laboratory in a few minutes with a cheek swab, and the result states the probability of the relationship. Done with the consent of everyone tested, and read by a geneticist.

With everyone’s consent
A cheek swab, a few minutes. Painless, at the laboratory, for every person tested.
Cheek swabPainless, a few minutes, at the laboratory
>99.99%Probability of paternity when the man is the father
100%Exclusion when he is not
Any ageFrom birth; under 18 with both parents' consent
Who can be tested

Three relationships, one method

The same DNA markers answer all three questions. The statistics differ, and for siblings the answer is stronger when a parent's sample is included.

  • Father and childThe usual case: a man wants to know whether a child is his. The child's mother can take part too, which makes the result even stronger.
  • Mother and childA maternity test, on the same principle, for situations where the biological link is in question.
  • Brothers and sistersFull or half siblingship for two people who are not sure how they are related. Adding a known parent sharpens the answer.
  • Other relativesGrandparent, aunt or uncle comparisons are possible in some situations. Ask when you call.
How it works

Four steps

Every person inherits one copy of each DNA marker from the mother and one from the father. The laboratory reads a set of these markers in each person and checks, marker by marker, whether the child's copies could have come from the tested adult.

Step 1

Call and schedule

We agree a time, explain who needs to come and which documents to bring, and answer any question before you decide.

Step 2

Samples at the laboratory

Each person gives a cheek swab and signs consent. For a child under 18 both parents or legal guardians sign. It takes a few minutes and does not hurt.

Step 3

Analysis

A panel of STR markers is read in every sample and compared. A father shares one copy at every marker; mismatches at several markers exclude him.

Step 4

Result, explained

The report gives the probability of the relationship and the marker table. A geneticist explains it to the people tested, in person or by the channel you choose.

The report

What the result says

Two outcomes are possible, and both are unambiguous.

Not excluded

The man shares a copy at every marker. The report states a probability of paternity above 99.99% and the combined paternity index behind it.

Excluded

The child carries copies at several markers that the man does not have. He cannot be the biological father. The probability is 0%.

Siblingship

Reported as a likelihood that the two people are full siblings, half siblings or unrelated. Including a parent's sample makes it decisive.

Questions

Common questions

Turnaround and the exact marker panel are confirmed by the laboratory before launch.

How accurate is it?

When the tested man is the biological father, the probability of paternity is above 99.99%. When he is not, he is excluded with certainty, because the child carries DNA copies he could not have passed on.

Does the mother have to take part?

No. A father and child are enough. Including the mother lets the laboratory identify which copies came from her, which makes the result even stronger, so we recommend it when possible.

Can a newborn be tested?

Yes. A cheek swab works from the first day of life. For any child under 18 both parents or legal guardians consent.

How reliable is a sibling test?

Siblings share DNA in a less fixed way than parent and child, so the result is a likelihood rather than a near certainty. Adding a sample from a known parent, or testing both parents of one sibling, makes the answer far stronger. We will tell you in advance what is achievable in your situation.

Does it hurt?

No. A soft swab is rubbed on the inside of the cheek for a few seconds. No blood is taken.

How long does it take?

A few working days from sample collection. The exact turnaround is confirmed when you schedule.

Can I order it online?

No. Because consent and identification are checked in person, the test is scheduled by phone and the samples are taken at the laboratory.

Related

Before the baby is born

If the pregnancy is ongoing, the question can be answered now, without touching it.

Book a time and bring identification

Call us to schedule. We explain the consent rules for your situation before you come in, and a geneticist explains the result after.

Consent and identification requirements follow the applicable law and the laboratory's procedure; the rules above are confirmed when scheduling. Marker panel, turnaround and legal-use documentation are confirmed by the laboratory before launch. The test establishes biological relationship; it is not medical advice.