Forensically valuable DNA can be found on evidence that is decades old.

Several factors can affect DNA stability such as sunlight, moisture, bacteria, and mold. When storing and transporting evidence that may contain DNA, it is important to keep the evidence dry and at room temperature.

Once the evidence has been secured in paper bags or envelopes, it should be sealed, labeled, and transported. Never place evidence that may contain DNA in plastic bags because plastic bags will retain damaging moisture. Consequently, not all DNA evidence will result in a usable DNA profile.

Common sources for forensic DNA evidence include:

  • Blanket, pillow, bed sheet
  • Clothing
  • Bottle, can, or glass
  • Dental floss
  • Eyeglasses
  • Facial tissue, cotton swab
  • Fingernail clippings
  • Ear wax
  • Gum
  • Hair w/roots or follicles
  • Hat
  • Post mortem tissue
  • Stamp or envelope
  • Teeth or dentures
  • Toothbrush or toothpick
  • Cigarette butt

Forensic samples can be used in any DNA testing scenario in the event that an individual is not available for testing.


If you have further questions, please view the Frequently Asked Questions page or contact a Certified DNA Specialist toll-free at 1-877-477-5661.