DNA to X-ray: Military has variety of tools to ID remains
Published 10:46 am Sunday, July 29, 2018
NEW YORK — The U.S. military remains released by North Korea on Friday will be sent to a military lab in Hawaii, where they’ll enter a system that routinely identifies service members from decades-old conflicts.
Identifications depend on combining multiple lines of evidence, and they can take time: Even after decades, some cases remain unresolved.
Dog tags found with the remains can help, and even scraps of clothing can be traced to the material used in uniforms. Teeth can be matched with dental records. Bones can be used to estimate height. And the distinctive shape of a clavicle bone can be matched to records of X-rays taken decades ago to look for tuberculosis, said Charles Prichard, a spokesman for the Defense POW/MIA Accounting Agency.
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If a DNA analysis is called for, samples are sent to a military DNA lab at Dover Air Force Base in Delaware.
Tiny samples of bone or teeth, no bigger than the amount of bone in the last joint of the pinkie finger, are enough to yield usable DNA, said Timothy McMahon, who oversees the Dover lab as director of Defense Department DNA Operations.
Each sample is sanded to remove surface contamination, ground to the consistency of baby powder, and then treated with a substance that dissolves the bone and leaves the DNA for analysis. That DNA is then compared with genetic samples from living people who are related to the missing.
The military has been collecting DNA from such family members since 1992, and has reached the relatives of 92 percent of the 8,100 service members who were listed as missing at the end of the Korean War, McMahon said.
The goal is to find bits of DNA in common between the known relatives and the unidentified remains, suggesting both belong to a particular lineage. One analysis develops a profile that combines what’s found at 23 spots in the DNA, for example.
By analyzing different kinds of DNA, lab scientists can look for markers passed down by generations of women, or of men, or of both sexes. The lab once linked remains to a great-great-great-great-grandniece who initially had no idea she was related to the missing service member, McMahon said.
Once a link is made, the lab estimates how strongly it suggests the remains belong to a particular person, and send the results back to Hawaii. There, it’s combined with the other lines of evidence.