Results of the recent investigation to identify remains removed from the Tomb of the Unknowns at Arlington National Cemetery likely will hinge on DNA, but not DNA from the nucleus of a cell. Rather, investigators are looking at circular DNA found in the mitochondria, a tiny structure that converts nutrients into energy for a cell. Mitochondrial DNA, inherited maternally, can remain intact long after nuclear DNA has degraded. Crime labs are beginning to use it to crack cold cases, and medical researchers have linked mutations in mitochondrial DNA with Alzheimer's, Parkinson's, neuromuscular diseases and blindness.
As interest peaks in mitochondrial DNA, so has the need for a standard to assure accuracy in sequencing mitochondrial DNA. Researchers at the National Institute of Standards and Technology are working on a Standard Reference Material for human mitochondrial DNA. The new standard will include thoroughly characterized mitochondrial DNA from two cell lines. Labs will use it to determine whether their methods and results are accurate. Also included will be information on 58 primer sets that labs can use to amplify specific portions of or the entire human mitochondrial DNA. When issued, the new mitochondrial DNA standard will be the third created by NIST to ensure accuracy in DNA typing.