Forensics
Maybe the most significant application of DNA Sequencing is in the field of forensics. With challenges such as low copy numbers, degraded and contaminated samples, and the need for precision demands a brief yet effective methodology of DNA sequencing in order to make progress with cases. PCR and capillary electrophoresis (CE) are the predominant methods of analyzing DNA strands in the field of forensics.
STR Analysis
Due to its several advantages such as short DNA templates, fast processing, multiplex amplification and digitized results, this method of sequencing is widely used throughout the world by several forensics labs. In China for instance, there are more than 27 million entries in its forensics database. NGS, when first introduced to the market was not compatible with STR analysis at all due to its short reads. However, time and technology has allowed for the advancement of NGS to the point where the readings are increasing thus increasing its usage with STR analysis. This usage has allowed for several conveniences such as cost-efficiency, being able to distinguish alleles and being able to locate several variants. This has allowed the costs for several legal cases to also decrease as the technology continues to get better.
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Mitochondrial Genome Analysis
This method has lowered the need for extensive DNA fragments and it focuses on genes passed on by the mother. Very similar to the processes involved in wildlife preservation, mtDNA takes a look at the polymorphism of certain regions within the DNA. In order to use this as a potential marker, more data must be collected in order for specific identification to be made.
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Forensic Microbiology Analysis
After 18 September 2001, microbial forensics became a new discipline through the efforts of the FBI when there was an Anthrax attack. Ever since the alarming possibility that terrorists can potentially use pathogens to launch an attack on other nations, this technique is becoming more and more prevalent and sought after. Through the use of whole genome sequencing, there have been efforts made to sequence four strains of Bacillus anthracis and Yersinia pestis. Using the 454 sequencing system can help with identifying biological traces along with the use of deep sequencing and metagenomic analysis.
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Epigenetic Analysis
The possibility of using epigenetic markers to distinguish between monozygotic (MZ) twins, predict tissue type, and to determine the age of a DNA donor makes epigenetic analysis highly attractive to forensics scientists. The case regarding MZ is gaining more momentum as attempts are being made to distinguish between two individuals who are essentially the same. Earlier approaches of STR analysis, mtDNA, and rRNA analysis fail to work since it cannot tell the two apart. In this case, only ultra-deep NSG on rare mutations can help solve the problem. A recent application of this technique was employed at King’s College, London where NGS was used to differentiate between 5000 pairs of twins.
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MicroRNA Analysis
This technique is a rather well established and it has been recently introduced as well. It uses small molecules analogous to RNA which is resistant to degradation, is tissue specific, aid in body fluid identification, species identification and post-mortem interval interference analysis. The analysis of these miRNA molecules is completed through PCR ad biochip technology.
Citations 9.1 - 9.4
Exploring the Depths of Life
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Sequencing
