How to Collect DNA sample for testing

There are many possible reasons for a collection of a DNA sample from yourself or another person. A number of laboratories offer easy to use home DNA kits to perform paternity tests, genealogy tests, or genetic screening for diseases. Many law enforcement authorities also request parents to collect DNA samples from their children for identification purposes. There are several methods on how to collect DNA samples, many of which are fairly non-invasive and painless. Depending on the DNA sample, DNA can be kept for many years if handled properly.


Part 1 Figuring out your needs

1 Decide if you need a kit. This will depend on why you need to perform DNA testing. If you need results certified by a laboratory, you will likely need to buy a kit. If you plan to store the sample, in case you will need it one day, you may not need a kit, however, you may still decide to get one if you want.

DNA test kits contain all of the materials you will need, as well as full instructions and consent forms that shall be completed if the samples shall be tested or registered by the authorities.


2 Verify legal requirements. Most usually DNA samples cannot be collected at home if they are to be used by a court. Although home paternity tests is a good choice to satisfy your own curiosity, you will likely need to contact a laboratory and have your DNA collected by a DNA testing specialist, for example, if you are required to use the testing results for matters involving custody or child support.


3 Choose the appropriate sample type. If you decide to use a kit, you will receive specific instructions stating what kind of samples you need to collect. If you are sending your samples to a laboratory without a kit, ask what kind of samples would be the most appropriate for testing.

  • Almost all DNA kits request either buccal (cheek) swabs or saliva samples, however, hair samples are also very popular.
  • It is possible to obtain DNA from almost any human sample, including nails, blood, sperm, and objects that contain saliva, such as chewing gum. Some samples, although, are less difficult to extract than others. If you choose a non-preferred sample type, the laboratory might not be able to extract DNA, or it might cost you more.


Part 2 Maintain the integrity of the sample

1 Do not have a physical contact with the sample. It is not important what kind of sample you collect, you should not touch it with your hands or place it on a contaminated surface. This is even more important if you want to obtain a DNA sample from another person, because you could possibly contaminate the sample with your own DNA.

Wash your hands before you begin DNA sample collection and never forget to wear gloves.


2 Use only clean and sterile equipment. A swab, tweezers, or clippers used for sample collection should be sterile, and you should avoid touching the part of the equipment that will come in contact with the specimen.

It is possible to sterilize metal equipment with alcohol or by boiling in water.


3 Store your specimen in a clean and dry container. Along with a kit you will receive collection containers and instructions to be followed to store it properly.

  • Paper envelopes are the best storage containers for almost all non-liquid samples. Do not store hair specimens or a damp buccal swab in a plastic bag, as this will retain moisture and may damage the DNA sample.
  • If you decide to store specimen in an envelope, do not lick the seal, as this could contaminate the sample.
  • If you plan to store the specimen for a potential use in the future, label it with the name of the person from whom the specimen was collected, the date of collection, and the name of the person who collected it.
  • Avoid the sample to become in contact with moisture, extreme temperatures and chemicals.


4 Act in compliance with packing and shipping instructions. If you use a DNA kit, the instructions will be very clear and you should follow them very attentively. If you are mailing your sample to a laboratory without a kit, make sure you follow shipping instructions.


Part 3 Sample collection

1 Swab your cheek. For buccal swabs, scrape your inner cheek with a sterile swab for up to sixty seconds. Scrape actively, but not until it starts hurting. Continue swabbing for at least 30-60 seconds. Once finished, make sure not to touch the end of the swab to any surface other than the inside of your mouth and the inside of the container.

  • Kits often request more than one swab, just in case one does not contain DNA. If you do not use a kit, you may still wish to use multiple swabs. To improve the amount of DNA collected, take two or more samples from different sides of the mouth, or take them several hours apart.
  • Do not eat, drink anything other than water, smoke, chew a gum, brush your teeth, or use mouthwash for at least one hour before taking the test.
  • Rinse the mouth with warm water ten minutes before swabbing. If a sample shall be taken from a baby, allow to drink water from a bottle before testing.
  • Wait the swab to get dry before storing.


2 Pull 10 to 20 strands of hair from the head. When collecting hair samples, make sure that the follicle, which looks like a small white bulb, is still attached.

  • Avoid using hairs from a hairbrush or clothing. It is also not possible to use cut hair.
  • Do not touch the follicle end of the hair.
  • Getting hair samples might be hurtful, especially if the hair is shiny and strong.


3 Collect a sample of saliva. The easiest way to do this is to drool into your DNA sample collection container. If you use a kit, you may be provided with sponges to make the collection of saliva from little children easier.

  • Do not eat, drink anything other than water, smoke, chew a gum, brush your teeth, or use mouthwash for at least one hour before taking the test.

Rinse the mouth with warm water ten minutes before collecting the DNA sample to remove any food particles. If a sample shall be taken from a baby, allow to drink water from a bottle before testing.


4 Collect other samples by following the same precautions. If you plan to collect less popular samples, for example, fingernails, blood, or semen, take every precaution to avoid touching or otherwise contaminating the samples. Contact the laboratory you plan to send the specimen to in order to confirm that they are able to extract DNA from the sample you can collect.