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Non-STR DNA Markers: SNPs, Y-STRs, LCN and mtDNA

Microbial DNA

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Terrorist attacks have raised awareness of the possible use of pathogens and toxins as bioweapons to commit bioterrorism and biocrime. Microorganisms and toxins have already been used in criminal offenses, such as the anthrax attacks of 2001.65 The field of microbial forensics has emerged in order to facilitate the identification of the infectious agent(s) used in a criminal offense, to determine the origin of such a sample, and to establish links to the perpetrators.  While current DNA profiling strategies including direct DNA sequencing and the analysis of appropriate microsatellites, minisatellites and SNPs can be used to identify microorganisms. The biology of microorganisms results in additional challenges for the forensic community. Microbial source attribution is often difficult due to the clonal nature of some microorganisms, and their rapid rate of evolution (i.e., mutation).08 The former could result in false associations between the evidence and the putative source, while the latter could result in false exclusions.

Although standard crime scene investigative processes involving the recording, collection, and preservation of evidence pertain to biocrime scene analysis, additional safety considerations apply due to the varying infectious nature of the evidence.08,09,66 Accordingly only personnel specifically trained to deal with the agents likely to be used in biocrime should process such scenes. Case-working crime laboratories are not equipped to handle infectious agents, many of which require the use of biohazard level 3 or 4 laboratories. Quality assurance and quality control guidelines for the collection and analysis microbial DNA samples, akin to those established for human DNA profiling, have been recommended.08,66,67

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