Fabricated DNA Evidence

In August 2009, scientists in Israel stunned the forensic sciences and raised serious questions concerning law enforcement's use of DNA matching as the ultimate method of identification. In a paper published in the journal Forensic Science International: Genetics, the Israeli researchers demonstrated that it is possible to manufacture DNA in a laboratory, and thus falsify DNA evidence. The scientists had fabricated saliva and blood samples, which originally contained DNA from a person other than the ostensible donor of the blood and saliva.[21]

Additionally, and perhaps more frighteningly, the same researchers showed that, using a DNA database, it is possible to take information from a profile and actually manufacture DNA to match it. Worse, this can done without access to any actual DNA from the person whose DNA they are duplicating. The synthetic DNA oligos required for the procedure are used in probably every molecular laboratory.[21]

Dr. Frumkin fortunately has perfected a test that can forensically differentiate real DNA samples from fake ones. His test uses epigenetic modifications, in particular, DNA methylation. Seventy percent of the DNA in any human genome is methylated, meaning it contains methyl group modifications within a CpG dinucleotide context. Methylation at the promoter region is associated with gene silencing. It appears that the synthetic DNA lacks this epigenetic modification, which allows the test to be used to distinguish manufactured DNA from original, genuine, DNA.[21]

The idea that DNA can be fabricated, and then planted at a crime scene, is now reality; fortunately Dr. Frumkin has developed the test to differentiate real from fake DNA. But it is unknown how many, if any, police departments currently use the test, which is distressing considering Frumkin’s claim that the DNA manufacturing procedure is within the grasp of any undergraduate biology student. No police lab has publicly announced that it is using the new test to verify DNA results, while FSI Genetics says that any forensic laboratory doing DNA identification should adopt this test to authenticate its results as "real" DNA.[22]

Source:
http://en.wikipedia.org/wiki/DNA_profiling
http://www.nytimes.com/2009/08/18/science/18dna.html?_r=2