DNA Sample Collection Instructions
DNA testing provides scientific certainty, but the accuracy of your results depends on proper sample collection and handling. Whether you’re testing for paternity, relationship DNA, or infidelity, following the correct procedures ensures the highest chance of obtaining clear and conclusive results. This guide outlines step-by-step DNA sample collection instructions, best practices, and how to properly package and ship samples for testing.
Standard DNA Sample Collection: Buccal (Cheek) Swabs
Buccal swabs are the most reliable and commonly used DNA collection method. They are preferred due to their high success rate, painless collection process, and rapid turnaround time.
How to Collect a Buccal Swab Sample
Wash Your Hands – Ensure hands are clean before starting the collection process.
Avoid Food or Drinks – Do not eat, drink, smoke, or chew gum at least 30 minutes before collecting the sample.
Use a Sterile Swab – Open the sterile swab provided in your collection kit, ensuring you do not touch the tip.
Rub the Swab Inside the Cheek – Firmly rub the swab against the inner cheek for 30-60 seconds to collect sufficient DNA.
Air Dry the Swab – Let the swab air dry for 5-10 minutes before placing it in the designated envelope.
Repeat for Additional Swabs – If multiple swabs are included, repeat the process on the opposite cheek using a new swab.
Place the Swabs in the Provided Envelope – Ensure swabs are fully dry before sealing the envelope.
✔ Processing Time: 2-3 business days after the sample reaches the lab. ✔ Success Rate: 99%+ when collected properly.
Non-Standard (Forensic) DNA Sample Collection
If a cheek swab is not an option, forensic DNA testing can be performed using special samples, including:
Hair (with root attached)
Used toothbrushes
Chewed gum
Nail clippings
Ear swabs/Q-tips
Bloodstains on fabric
Used tissues or condoms
Cigarette butts
✔ Processing Time: 5-7 business days due to additional forensic extraction.
✔ Success Rate: Lower than buccal swabs, as not all samples contain viable DNA.
Best Practices for Collecting Forensic DNA Samples
To improve the likelihood of obtaining a viable DNA profile, follow these best practices:
Minimize Handling – Wear clean gloves and use tweezers to avoid contamination.
Choose the Best Sample – Ensure items have been recently used and contain biological material.
Air Dry Before Packaging – If the sample is wet, allow it to dry completely to prevent bacterial growth.
Store in Paper Envelopes – Do not use plastic bags, as they trap moisture and degrade DNA.
Label Each Sample Clearly – Indicate the source and date of collection.
For the best results, it’s recommended to submit multiple samples if available.
Proper Packaging & Shipping Instructions
To ensure your samples arrive at the lab in the best condition, follow these steps:
Place Each Sample in a Paper Envelope – Keep all items separate to avoid cross-contamination.
Use a Secure Mailing Envelope or Box – Place all sample envelopes inside a larger envelope or shipping box.
Choose a Trackable Shipping Method – Use USPS, FedEx, or UPS for reliable delivery.
Avoid Extreme Temperatures – Store and ship samples in a cool, dry place.
Notify the Lab If Using a Special Sample – If submitting forensic samples, inform the lab for proper processing.
How Long Does DNA Last in Samples?
DNA can remain viable for testing depending on storage conditions and material type:
Buccal Swabs: DNA remains intact for several months when stored in a dry, cool place.
Hair (with root attached): Can retain DNA for years under proper conditions.
Toothbrushes & Gum: DNA may last weeks to months but degrades faster if exposed to bacteria.
Clothing & Fabric Stains: Can retain DNA for months to years if stored in a dry, dark place.
For the most accurate results, send samples as soon as possible after collection.
Key Takeaways for Accurate DNA Collection
Buccal swabs are the gold standard for DNA collection—use them whenever possible.
If using forensic samples, choose recently used items and handle them with care.
Air-dry all samples before packaging to prevent DNA degradation.
Store samples in paper envelopes, never plastic.
Ship samples promptly using a reliable courier.
At Validity Genetics, we ensure every DNA test is handled with precision and confidentiality. Follow these collection instructions for the most accurate and reliable DNA results.
