How to Collect a DNA Sample

There are various reasons you might want to collect a DNA sample from yourself or a loved one. Nowadays, there are many home DNA collection kits designed for purposes such as determining paternity, establishing lineage, or conducting genetic screening for diseases. Law enforcement agencies also encourage parents to collect DNA samples from their children for identification purposes. There are non-invasive and pain-free methods for collecting DNA samples. Depending on the sample type, DNA can be preserved for many years if handled properly.

Determine if you need a DNA collection kit. This depends on the purpose of your sample collection. You might need a kit if you plan to use the DNA sample for testing purposes. However, if you're only storing the sample for future reference, you might not need the kit, although it's still available for purchase if desired.

• The DNA collection kit contains all the necessary tools, a comprehensive instruction manual, and a consent form required for testing the DNA sample or for use by authorities to maintain records.

Check the Legal Requirements. In most cases, you are not allowed to collect a DNA sample at home if the test results are to be used in court. A home-collected DNA sample for paternity testing can provide results, but if you need to go to court for child custody or child support issues, you'll have to visit a lab where a professional will collect the sample.

Identify the Correct Sample Type. If you are using a DNA collection kit, the kit will come with specific instructions on which type of sample to collect. If you're sending a sample to a lab without a kit, be sure to ask the staff there about the type of sample they require.

• Most kits request either a cheek swab or saliva sample. Hair is also a commonly used sample.
• DNA can generally be collected from almost any part of the body, including nails, blood, semen, and saliva-contaminated items like chewing gum. However, some samples are easier to obtain usable DNA from than others. If you collect an unsuitable sample, the lab might not be able to extract DNA, or it could be more expensive to process.

Avoid Touching the Sample. No matter the type of sample, you should not touch it with your hands or place it on a surface that could cause contamination. This is especially critical when collecting a DNA sample from someone else, as your own DNA might accidentally transfer to the sample.

• Wash your hands thoroughly before handling the sample, and always wear gloves.

Use Sterile Tools. If the sample collection process requires cotton swabs, tweezers, or nail clippers, you must disinfect the tools and avoid touching the parts that will come in contact with the sample.

• You can sterilize metal tools with alcohol or by boiling them in water.

Store the Sample in a Dry, Clean Container. The collection kit includes containers for storing the sample along with instructions on how to store it properly.

• An envelope is the best container for most samples that do not contain liquids. Do not store hair samples or cotton swabs with saliva in plastic bags, as these can trap moisture and damage the DNA.
• If you store the sample in an envelope, avoid licking the adhesive flap, as this could contaminate the sample.
• If you're storing the sample for future use, be sure to label it with the owner's name, the date the sample was collected, and the name of the person who took the sample.
• Keep the sample in a dry place, away from chemicals, extreme temperatures, or humidity.

Follow the Packaging and Shipping Instructions. The kit instructions are very clear, so follow them exactly if you're using a collection kit. If you plan to send the sample to a lab without using a kit, be sure to fully understand the shipping guidelines.

Use a Cotton Swab Inside Your Cheek. For a cheek sample, use a sterile cotton swab to rub the inside of your cheek for about one minute. Rub firmly, but without causing pain. Continue rubbing for at least 30-60 seconds. Once you're done, make sure the swab doesn't touch any surface except inside your mouth and the container.

• Most sample collection kits ask for two or more cotton swabs, in case one doesn't contain enough DNA. However, even without a kit, you can take multiple swabs. To maximize the amount of DNA collected, it's recommended to take swabs from both cheeks or take samples several hours apart.
• Do not eat or drink anything other than water, smoke, chew gum, brush your teeth, or use mouthwash at least one hour before collecting the sample.
• Rinse your mouth with warm water for 10 minutes before collecting the sample. For small children, allow them to drink water from their own cup before taking the sample.
• Let the swab dry before storing it.

Pluck 10-20 Hair Strands. When collecting a hair sample, make sure the root bulb, the small white bulb at the hair's base, is attached.

• Do not use hair that was left behind on a comb or clothing. Cut hair is also not suitable for testing.
• Avoid touching the root of the hair.
• It may cause some pain when plucking hair, especially if the hair is thick and strong.

Collecting a Saliva Sample. The best way to collect a saliva sample is to let the saliva drip into the sample container. If you're using a collection kit, it may include sponges that help collect saliva from young children.

• Do not eat, drink anything other than water, smoke, chew gum, brush your teeth, or use mouthwash for at least one hour before collecting the sample.
• Rinse your mouth with warm water for 10 minutes before taking the sample to remove any food particles that may be left in your mouth. If you're collecting a sample from a young child, have them drink from their own bottle before collecting the sample.

Collect Other Samples with the Same Care. If you are collecting less common samples such as nails, blood, or semen, exercise extreme caution to avoid contamination or mishandling. Consult with the laboratory about your plans to send the samples to ensure they can successfully extract DNA from the collected samples.

• DNA sample collection kit
• Sterile cotton swabs
• Sterile containers and envelopes
• Plastic bags
• Rubber gloves
• Soap
• Water