DNA Analysis Stars in GWAT

In an age when even the president has to offer up his birth certificate to prove he was born in the U.S., it’s probably not going to be easy to convince skeptics that the world’s best known terrorist leader is dead.Perhaps a little DNA fingerprinting will do the trick in this bit of the Global War on Terror (GWAT).Among the flurry of stories about the demise of Osama bin Laden at the hands of American Special Forces are a few regarding the science behind how his identity was confirmed. Beyond just seeing him with their own eyes and talking to his family – one of his wives reportedly confirmed the man killed was indeed Bin Laden – the team of Navy SEALs reportedly used DNA fingerprinting to offer the final proof.

In a wonderful post at the Scientific American, guest blogger Christie Wilcox breaks down the steps for a fast DNA fingerprinting process that could be done in less than five hours.Wilcox lists how a DNA sample could be quickly extracted and then specific regions of interest amplified using PCR (short for “Polymerase Chain Reaction”). The regions of interest are places where short sequences of DNA repeat themselves a variable numbers of times. The more closely two people are related, the more likely it is for the numbers of repeats in each region to match. And if two samples are identical, the numbers of repeats will be also be identical.The sample could be compared against another sample to verify identity or relatedness.In the case of Bin Laden, several news sources reported that authorities had gotten DNA samples from his family members, including one from his sister who died recently at a hospital in Boston.Kit Eaton, at FastCompany, writes about another type of DNA matching using technology similar to 23andMe’s genotyping test that typically takes about two weeks to complete but in this case could be done in as little as two hours.A key difference between DNA fingerprinting and the genotyping done by 23andMe is the type of DNA variation being looked at.Traditional forensic DNA fingerprinting looks at the lengths of short, repeated DNA sequences, while 23andMe’s genotyping technology analyzes a person’s DNA for specific locations where the sequence is known to vary, for example from an “A” to a “C”.Our current genotyping platform looks at nearly 1 million such locations across the entire genome. This amount of DNA data is enough to give a broad range of information on both health and ancestry. In the case of relatives, it easily identifies close family members, but can also identify more distant cousins who share even small segments of identical DNA.
  • It was not clear from any report what kind of test they have performed for this purpose. Did they performed CODIS STR marker test (which is established test by FBI) ? or did they used Y chromosome marker test ? or did they use some thing else? “99.9 % match” is a very vague scientific term for DNA fingerprinting. Using genome wide markers ~ 1 million would also increase the chance of getting false positive results due to high level of noise and quality control issues & that is the reason why this CODIS is still acceptable and genome wide markers is not validated enough for this purpose.

  • Eric

    Fascinating! How fast, with technology we have now, can a match like that be made?

  • Larry

    I feel obliged to point out that simply saying, “We ran a DNA test,” is not proof, or even evidence, of anything. It is still merely a bald assertion.

    I hope that the American government will actually make samples available to independent world labs, so that they can run their own tests.

  • Ian

    For all the “Osama DNA matches” headlines, there doesn’t seem to be a single actual datum reported anywhere at this time.

    This is not too surprising at this point, but I also would like to know at least what tests [were/will be] done and what data the public [might/might not] be able to view.

    I am no “birther” and I don’t plan to be a “deather”, but I do feel a sense of entitlement to the raw data, as an American taxpayer who has funded the “GWAT” for so many long wasteful years (btw, I hate that acronym).

    Incidentally, does anyone know if data from any immediate family members of Bin Laden are publicly available?