How are Samples Collected for a Non-Invasive Prenatal Paternity Test

Samples for non-invasive testing will always require a blood withdrawal from the mother. The test relies on the analysis of cell free fetal DNA in the maternal blood stream. However, the sample for the alleged father can either be blood or a mouth swab sample.

Different companies might require your collect samples in a different week of pregnancy. The test can usually be carried out at 9 weeks from conception (this means you will be in your 11th week of pregnancy, starting from the first day of your last menstrual period). However, some companies might require you collect the blood at a later stage.

What the kit contains

All non-invasive prenatal paternity testing kits will contain the following items or similar items. There may be slight variations in the terminology used. The main variation will depend on whether the father’s sample is a venal blood sample or a sample collected using sterile buccal swabs.

The following is what you will find:

  • Instruction leaflet explaining how samples are collected.
  • 2 x 10-ML Blood Collection Tube (BCT) to be used for the maternal blood sample.
  • A bar code label will be provided. You will use this to label the 10-ML blood collection tubes above.
  • A special biohazard bag with zip to place DNA samples in.
  • Boxing, packaging, return labelling and Exempt Human Label (a hazardous shipping label for human or animal biological substances to mark containers that contain excretions, blood or human tissue).
  • Consent forms (please fill these out carefully and return them with your samples)

The father’s samples:

It is worth stating a second time that some prenatal kits will contain oral swabs for the father whilst others will contain blood collection tubes.

If the Prenatal test uses blood for alleged father you will usually have just 1 x 6-ML tube containing a blood preservative and anticoagulant known as K2-EDTA. A bar-coded label will be provided for you to label this tube.

If the prenatal test uses mouth swabs, you will have an envelope containing 4 cotton-like mouth swabs. You will just need to write some basic details on the envelope containing the swabs.


Kits containing mouth swab samples carry a huge added advantage over kits containing blood collection tubes since the test participants themselves can collect the oral swab samples in the ease and comfort of their own home. Mouth swab samples are collected by simply rubbing the swabs provided inside the mouth for ten seconds and then allowing them to dry for one hour. Blood samples must be collected by a qualified nurse, doctor or phlebotomist and there will be an additional fee set for collecting the blood sample.

Collecting your blood samples

Blood samples for a non invasive prenatal paternity test need to be collected by a qualified person and you will be responsible for finding a qualified person to withdraw the blood. Make sure to take your kit and all its contents with you. DNA testing companies will not accept blood collection tubes that were not contained inside the kit they provide.

The blood draw is a standard, venous blood draw, collected from the arm. The nurse or phlebotomist will first wipe the area with an alcohol wipe and then proceed to insert the needle in order to extract the required blood. Because blood samples cannot be stored for long without affecting the DNA inside them, it is strongly recommended you organise the blood draw on the same day as the sample shipment. Avoid keeping blood samples for more than a day.

Return of samples to the laboratory is done by means of a courier service which is included in the price of the test.

Once samples are collected and consent forms filled in, pack them following the instructions inside the kit and send them off for testing.