What contamination looks like
Contamination means DNA from someone other than the intended donor ends up on the sample. It can make a profile unreadable or produce a mixture that cannot be interpreted.
Practical rules
- Clean, dry hands before touching any collection material
- Never touch the swab tip or the business end of a personal item
- One donor at a time, sealed and labelled before moving on
- Air dry fully; moisture encourages bacterial growth
- Use paper envelopes, never sealed plastic bags
- Store at room temperature away from direct sunlight and heat
Do not attempt to clean an item
Washing or wiping a toothbrush or similar item removes the very cells that would be analysed.
If something goes wrong
Tell us before shipping. It is faster to recollect than to wait for an inconclusive laboratory outcome.