Hair DNA testing is possible, but the quality of the results reduces with increased age of the hair: age meaning time since it was removed from the head. Useful samples should have the follicles still attached, and preferably have been taken deliberately rather than shed naturally. Cut hair cannot be used for testing, and as a general rule pluck a minimum of 5 strands from the head, make sure the roots (follicles) are still attached and send them to us immediately. The quality of the DNA begins to drop immediately the hair is removed.