Long-Read Sequencing Technique As A Powerful Tool In Forensic Investigations

In the past twenty years, the statistical data on murders in USA stated that males account for most of the violent crimes. The work of the forensic analyst is very hard when dealing with evidence coming from a vaginal swab in a rape case, as the samples present mixtures. Because of this, the interpretation of the results is sometimes not enough to identify the perpetrators.


The possibility to use markers on Y chromosome becomes a necessity when other analysis fails.


In her poster at ISHI 30, Fabiana Tagila presents a study in which she works to develop and optimize a method to sequence long reads (including YSTRs and YSNPs) together and demonstrates that this kind of analysis can represent a very powerful tool in forensic genetic analysis.


This project represents one of the first studies to analyze these polymorphisms using the MinION, a portable sequencing device produced by Oxford Nanopore Technologies.





Travis: Good morning Fabiana!


Fabiana: Good morning!


Travis: I see that you have a poster here: “The Long-Read Sequencing Technique, and Its Application to Y-Chromosome as a Powerful Tool in Forensic Investigations.” Would you please tell me what all that means?

Fabiana: My poster is about the long-read sequencing technique and its application to the Y-Chromosome as a powerful tool in forensic investigation. My big purpose is trying to help those investigations in which, sometimes, we don’t have any witnesses. Or there are multiple perpetrators, and in which, sometimes, you know, you can have problems in the normal STR analysis with the capillary electrophoresis. So, what I want to use is a new sequencing technique. It’s a fieldable. It’s a minION. They use nanopore techniques to sequence the DNA, but my application is on the longer read on the Y-chromosome.


So far, there have been some studies on the use of the MinION for the sequencing technique, not too much for the application for the forensics. So, I would like to see what happens when I sequence the longer read fragment around the base region of the Y-Chromosome that contains the Y-STR and SNPs.


So, my aim is to try to use this as an additional tool for human identification in those cases where you have more than one of the same members of a family that can be the perpetrator or also trying, in the future, to help the deconvolution of mixtures too. It’s a hard matter and topic in forensics.


I hope that with this technique we might be able to help the forensic investigation – trying to solve crimes, and I really think that it would be a nice addition.


Travis: That’s great. Well thank you very much. I really appreciate your time and have fun at ISHI 30.


Fabiana: Of course I will have fun, Travis! Thank you so much!