From National Institute of Standards and Technology (NIST)
NIST advances in DNA analyses help Identify 9/11 victims Remains from 16 additional victims of the Sept. 11 attacks on the World Trade Center have been positively identified thanks in part to a new method for analyzing DNA developed with assistance from the National Institute of Standards and Technology (NIST).
Based on a concept developed at NIST, the new method allows accurate identification of DNA samples that are too damaged or degraded to be analyzed with conventional procedures. The NIST research was funded by the National Institute of Justice.
The matching of more than 20,000 recovered bone and tissue remains from the World Trade Center site with DNA samples provided by relatives of presumed victims is the largest DNA identification effort ever undertaken. Remains from about half of the approximately 2,800 victims were identified previously with standard DNA analyses.
One of several advanced analysis techniques being used in the WTC identification effort, the new method reduces the size of DNA fragments needed for a positive identification. Conventional forensic methods using "short tandem repeats, or STRs" analyze DNA fragments from 13 specific locations within the human genome. Each fragment contains approximately 200 to 400 pairs of the nitrogen-containing compounds or "base pairs" that comprise the genetic code of an individual.
The NIST approach uses fragments that come from the same 13 locations but are substantially smaller, with roughly 25 to 190 fewer base pairs depending on the location. The smaller size means that damaged or degraded DNA samples are more likely to have intact sections at each of the 13 specific locations. This research will be described in an upcoming issue of the Journal of Forensic Sciences.
The ongoing effort to identify additional damaged or degraded WTC remains is being carried out by a group of government agencies and industry contractors under the leadership of the New York City Medical Examiner's Office.