DNA has been one of the most important, possibly the most important, advances in forensic science. When DNA is available, the issue of identity simply drops from the case. A few years back, the anti-DP crowd's poster boy for the executed "innocent," Roger Coleman, was conclusively proven guilty by DNA. It was a great moment.
Now the conclusiveness of DNA is in jeopardy. An article in Forensic Science International: Genetics says, "It turns out that standard molecular biology techniques such as PCR, molecular cloning, and recently developed whole genome amplification (WGA), enable anyone with basic equipment and know-how to produce practically unlimited amounts of in vitro synthesized (artificial) DNA with any desired genetic profile." The authors propose a method for distinguishing real crime-scene DNA from fake.
We have already seen in the Kevin Cooper case how someone who appears to have been conclusively proven guilty with DNA can drag out litigation for years with tampering claims. No doubt fabrication claims based on this article are coming soon to a courtroom near you. Andrew Pollack has this article in the NYT.
Abstract of the journal article is after the jump.
Now the conclusiveness of DNA is in jeopardy. An article in Forensic Science International: Genetics says, "It turns out that standard molecular biology techniques such as PCR, molecular cloning, and recently developed whole genome amplification (WGA), enable anyone with basic equipment and know-how to produce practically unlimited amounts of in vitro synthesized (artificial) DNA with any desired genetic profile." The authors propose a method for distinguishing real crime-scene DNA from fake.
We have already seen in the Kevin Cooper case how someone who appears to have been conclusively proven guilty with DNA can drag out litigation for years with tampering claims. No doubt fabrication claims based on this article are coming soon to a courtroom near you. Andrew Pollack has this article in the NYT.
Abstract of the journal article is after the jump.
Authentication of forensic DNA samples
Dan Frumkina, Adam Wasserstroma, Ariane Davidsona, Arnon Grafitb
Received 3 April 2009; received in revised form 11 June 2009; accepted 16 June 2009. published online 17 July 2009.
Corrected Proof
Abstract
Over the past twenty years, DNA analysis has revolutionized forensic science, and has become a dominant tool in law enforcement. Today, DNA evidence is key to the conviction or exoneration of suspects of various types of crime, from theft to rape and murder. However, the disturbing possibility that DNA evidence can be faked has been overlooked. It turns out that standard molecular biology techniques such as PCR, molecular cloning, and recently developed whole genome amplification (WGA), enable anyone with basic equipment and know-how to produce practically unlimited amounts of in vitro synthesized (artificial) DNA with any desired genetic profile. This artificial DNA can then be applied to surfaces of objects or incorporated into genuine human tissues and planted in crime scenes. Here we show that the current forensic procedure fails to distinguish between such samples of blood, saliva, and touched surfaces with artificial DNA, and corresponding samples with in vivo generated (natural) DNA. Furthermore, genotyping of both artificial and natural samples with Profiler Plus® yielded full profiles with no anomalies. In order to effectively deal with this problem, we developed an authentication assay, which distinguishes between natural and artificial DNA based on methylation analysis of a set of genomic loci: in natural DNA, some loci are methylated and others are unmethylated, while in artificial DNA all loci are unmethylated. The assay was tested on natural and artificial samples of blood, saliva, and touched surfaces, with complete success. Adopting an authentication assay for casework samples as part of the forensic procedure is necessary for maintaining the high credibility of DNA evidence in the judiciary system.
Keywords: Artificial DNA, Methylation analysis, DNA authentication, Forensic science
a Nucleix Ltd., 27 Habarzel St., Tel Aviv 69710, Israel
b Serious Crime Unit Mobile Lab., Division of Identification & Forensic Science, Israel Police, Israel
Corresponding Author Information. Tel.: +972 3 768 4935; fax: +972 3 768 4945. dan@nucleix.com adam@nucleix.com
Dan Frumkina, Adam Wasserstroma, Ariane Davidsona, Arnon Grafitb
Received 3 April 2009; received in revised form 11 June 2009; accepted 16 June 2009. published online 17 July 2009.
Corrected Proof
Abstract
Over the past twenty years, DNA analysis has revolutionized forensic science, and has become a dominant tool in law enforcement. Today, DNA evidence is key to the conviction or exoneration of suspects of various types of crime, from theft to rape and murder. However, the disturbing possibility that DNA evidence can be faked has been overlooked. It turns out that standard molecular biology techniques such as PCR, molecular cloning, and recently developed whole genome amplification (WGA), enable anyone with basic equipment and know-how to produce practically unlimited amounts of in vitro synthesized (artificial) DNA with any desired genetic profile. This artificial DNA can then be applied to surfaces of objects or incorporated into genuine human tissues and planted in crime scenes. Here we show that the current forensic procedure fails to distinguish between such samples of blood, saliva, and touched surfaces with artificial DNA, and corresponding samples with in vivo generated (natural) DNA. Furthermore, genotyping of both artificial and natural samples with Profiler Plus® yielded full profiles with no anomalies. In order to effectively deal with this problem, we developed an authentication assay, which distinguishes between natural and artificial DNA based on methylation analysis of a set of genomic loci: in natural DNA, some loci are methylated and others are unmethylated, while in artificial DNA all loci are unmethylated. The assay was tested on natural and artificial samples of blood, saliva, and touched surfaces, with complete success. Adopting an authentication assay for casework samples as part of the forensic procedure is necessary for maintaining the high credibility of DNA evidence in the judiciary system.
Keywords: Artificial DNA, Methylation analysis, DNA authentication, Forensic science
a Nucleix Ltd., 27 Habarzel St., Tel Aviv 69710, Israel
b Serious Crime Unit Mobile Lab., Division of Identification & Forensic Science, Israel Police, Israel
Corresponding Author Information. Tel.: +972 3 768 4935; fax: +972 3 768 4945. dan@nucleix.com adam@nucleix.com
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