Army Lt. Col. Julius Smith -- chief of past conflict repatriation for Army Casualty and Mortuary Affairs -- said Wednesday the military maintains the database of mitochondrial DNA samples of family members of MIA soldiers to help the Army identify recovered remains so they can be returned to families, the Armed Press Services reported.

Mitochondrial DNA is used for identification because it can be extracted from skeletal remains, said Linda Baublitz of the Past Conflict Repatriation Branch. Mitochondrial DNA, collected through an oral swab kit mailed to the donor, is passed only through the maternal line so the Army has to locate eligible donors from the mother's side of missing soldiers' families.

Volunteers from veterans' groups are helping track down the families.

"It's hard to keep in touch with (the families) now, because most of them ... are now getting older," said Carolyn Floyd of the Past Conflict Repatriation Branch.

Anyone who knows of a family with an unaccounted-for soldier can call 1-800-892-2490 or send an e-mail to tapscper@conus.army.mil.