The Sanger sequencing method was introduced in the 1970's, which led to enormous advances in molecular biology and genetics. However, the method did have several disadvantages, including low throughput, high cost, and operation difficulties. The introduction of next-generation sequencing (NGS) technology has seemingly overcome these issues, and researchers are now working to further develop the technology to apply to various fields. including forensic science.
DNA analysis is an incredibly important tool in forensic science, where in forensic DNA tests today employ PCR and capillary electrophoresis (CE)-based fragment analysis to detect length variations in short tandem repeat (STR) markers. CE-based analysis, though, comes with several limitations, including the inability to analyze multiple genetic polymorphisms in a single reaction using a single workflow, low resolution mtDNA and mixture analysis, and low-resolution genotyping of current markers. NGS technology allows for the ability to sequence millions to billions of DNA molecules in parallel, increasing the throughput and minimizing the need for the fragment-cloning method used in Sanger sequencing. It includes second- and third-generation sequencing technology, which can analyze a large number of samples simultaneously and determine the base composition of single DNA molecules, respectively. The limitations presented by CE-based analysis are therefore pushing researchers to further explore the potential for NGS technology in forensic science.
DNA sequencing is also an important tool in forensic identification, and a number of recent studies have found evidence supporting the idea that epigenetic markers could be used to distinguish monozygotic (MZ) twins, predict tissue type, and accurately determine the age of a DNA donor. It is thought that information within the human genome could provide insight into a person's characteristics such as ethnicity, physical and psychological characteristics, and age. It is a real possibility for next-generation sequencing to be used in the future to infer a criminal suspect's physical, psychological, and geographical characteristics from biological samples collected from crime scenes.
Although NGS seems to have a future in forensic science, it still has a long way to go and several obstacles to overcome, including the generation of guidelines for its application in the field, before we will see it put to use.
Source:
http://www.sciencedirect.com/science/article/pii/S1672022914001053
Lucio Avellaneda
ReplyDeleteAfter a while of using one method such as Sanger people get anxious about wanting to be able to have cheaper methods but also more efficient methods. Right now we are using PCR for many DNA processes but I wonder how long this will last.
Anyway it is important to be able to do this as we need more accurate, faster, and effective equipment that can cover the issues you see such as the twins you mentioned.
I like how we are starting to see the different methods that are overtaking older one and so on. It just serves to show how far we are coming along in science! The more that is learned and discovered, the more that efficient new methods will be made.
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