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Research Article

Resolving Individuals Contributing Trace Amounts of DNA to Highly Complex Mixtures Using High-Density SNP Genotyping Microarrays

  • Nils Homer,

    Affiliations: Translational Genomics Research Institute (TGen), Phoenix, Arizona, United States of America, University of California Los Angeles, Los Angeles, California, United States of America

    X
  • Szabolcs Szelinger,

    Affiliation: Translational Genomics Research Institute (TGen), Phoenix, Arizona, United States of America

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  • Margot Redman,

    Affiliation: Translational Genomics Research Institute (TGen), Phoenix, Arizona, United States of America

    X
  • David Duggan,

    Affiliation: Translational Genomics Research Institute (TGen), Phoenix, Arizona, United States of America

    X
  • Waibhav Tembe,

    Affiliation: Translational Genomics Research Institute (TGen), Phoenix, Arizona, United States of America

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  • Jill Muehling,

    Affiliation: Translational Genomics Research Institute (TGen), Phoenix, Arizona, United States of America

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  • John V. Pearson,

    Affiliation: Translational Genomics Research Institute (TGen), Phoenix, Arizona, United States of America

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  • Dietrich A. Stephan,

    Affiliation: Translational Genomics Research Institute (TGen), Phoenix, Arizona, United States of America

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  • Stanley F. Nelson,

    Affiliation: University of California Los Angeles, Los Angeles, California, United States of America

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  • David W. Craig mail

    dcraig@tgen.org

    Affiliation: Translational Genomics Research Institute (TGen), Phoenix, Arizona, United States of America

    X
  • Published: August 29, 2008
  • DOI: 10.1371/journal.pgen.1000167

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Copy of the press release originally distributed on August 27, 2008

Posted by PLoS_Genetics on 08 Sep 2008 at 16:20 GMT

* Scientists uncover new field of research that could benefit crime scene forensics *

A team of investigators led by scientists at the Translational Genomics Research Institute (TGen) has found a way to identify possible suspects at crime scenes using only a small amount of DNA, even if it is mixed with hundreds of other genetic fingerprints. Using genotyping microarrays, the scientists were able to identify an individual’s DNA from within a mix of DNA samples, even if that individual represented less than 0.1 percent of the total mix. They were able to do this even when the mix of DNA included more than 200 individual DNA samples. The results appear August 29th in the open-access journal PLoS Genetics.

The discovery could help police investigators better identify possible suspects, even when dozens of people over time have been at a crime scene. It also could help reassess previous crime scene evidence, and it could have other uses in various genetic studies and in statistical analysis.

“This is a potentially revolutionary advance in the field of forensics,” said the paper’s senior author, Dr. David W. Craig, associate director of TGen’s Neurogenomics Division, which is otherwise charged with finding ways to treat diseases and conditions of the brain and nervous system. “By employing the powers of genomic technology, it is now possible to know with near certainty that a particular individual was at a particular location, even with only trace amounts of DNA and even if dozens or even hundreds of others were there, too.”

Currently, it is difficult for police forensic investigators to detect an individual if their genomic DNA is less than 10 percent of a mix, or if it is from a large mix of DNA material. A long-held assumption within the field of forensic science – now being overturned – was that it was not possible to identify individuals using pooled data.

According to Commander Brent Vermeer, director of the Phoenix Police Department crime lab, much DNA evidence is rendered useless because of contamination, and that to eventually put the TGen theoretical research into a cost-effective police practice “would be an amazing asset.”

A new Arizona law, Senate Bill 1412, passed in June by the Legislature, requires police agencies to keep DNA evidence in cases of homicide or felony sexual assault for as long as convicts are in prison or on supervised release, or at least 55 years in unsolved cases. Some like Phoenix keep it indefinitely.

“As technology advances, we need to be prepared to keep evidence that, down the road, could prove again to be useful,” said Vermeer, who heads a bureau of nearly 130 analysts and crime scene investigators.

Dr. Stanley F. Nelson, director of the UCLA site of the National Institute of Health’s Neuroscience Microarray Consortium, said forensics investigators are “often stymied” because they now search for fewer than 20 DNA markers. The TGen researchers looked at hundreds of thousands of markers to make their identifications, he said.


RE: Copy of the press release originally distributed on August 27, 2008

PLoS_Genetics replied to PLoS_Genetics on 08 Sep 2008 at 16:23 GMT

The following links provide access to some of the news/blog coverage since publication. The journal is not responsible for the content of external sites; some external sites may require registration to view the full article; readers are welcome to judge the merits of each piece, considered in conjunction with the open-access article, http://www.plosgenetics.o... for themselves.

- Los Angeles Times: http://www.latimes.com/ne...
- ScienceNow Daily News: http://sciencenow.science...
- Financial Times: http://www.ft.com/cms/s/0...
- Times Online: http://www.timesonline.co...
- The Scientist: http://www.the-scientist....
- Birmingham Star: http://story.birminghamst...
- The Arizona Republic: http://www.azcentral.com/...
- Discover: http://blogs.discovermaga...
- Portfolio.com: http://www.portfolio.com/...
- The OpenHelix Blog: http://www.openhelix.com/...
- Newspost Online: http://www.newspostonline...
- Genome Web Daily News: http://www.genomeweb.com/...
- SmasHits.com: http://news.smashits.com/...
- TS-Si: http://ts-si.org/content/...
- "i On Global Trends": http://ionglobaltrends.bl...
- BioInform: http://www.bioinform.com/...
- Slashdot: http://yro.slashdot.org/y...


An additional news story

PLoS_Genetics replied to PLoS_Genetics on 10 Sep 2008 at 08:25 GMT

Article and letter in Science

PLoS_Genetics replied to PLoS_Genetics on 23 Sep 2008 at 11:54 GMT

An article in Science, 'GENETIC PRIVACY: Whole-Genome Data Not Anonymous, Challenging Assumptions' (http://www.sciencemag.org...) and a letter entitled 'Protecting Aggregate Genomic Data' from Elias Zerhouni and Elizabeth Nabel (http://www.sciencemag.org...) are also highly relevant.

A summary of the issues at stake can be found at http://www.phgfoundation.....