Aug 10 2017
Under the Microscope – Scott Kennedy
The ISHI agenda is live and includes great talks from amazing speakers! While the forensic community is a tight-knit group, we can always get a little closer, right? With that in mind, we interviewed our speakers to preview their presentations and to get to know them a little better outside of their work. We’ve been posting their responses in a feature we like to call Under the Microscope.
Today, we’re chatting with Scott Kennedy, who will be presenting Removing Sequencer and PCR Artifacts for Forensic DNA Analysis on Massively Parallel Sequencing Platforms during the General Sessions on Wednesday, October 4th.
Can you briefly explain what a minor allele frequency is, and why it is difficult for labs to identify individuals at this frequency?
Minor allele frequency is the second most common allele in a given population. Normally this term refers to single nucleotide polymorphisms in the human population. However, one can have a minor allele frequency within a population of DNA molecules, where a smaller population of DNA molecules have a different genotype. If the frequency of this minor allele is below the threshold of detection for a given assay, then this allele cannot be confidently called.
What is an artifact and how does these impact analysis?
Artifacts are spurious signal that give the appearance of particular genotype, but are not real. In conventional STR genotyping, which rely on length based polymorphism, PCR stutter is the primary source of artifacts.
How can Duplex Sequencing improve current laboratory workflow?
The major advantage of Duplex Sequencing is its accuracy. Duplex Sequencing is able to more confidently distinguish between sequencing and PCR artifacts, such as stutter, and true minor alleles within a population of DNA molecules.
Do you foresee MPS becoming the standard in forensic laboratories in the future? If so, when?
Given the rate of technological advance and rate of adoption of MPS in other scientific fields, I believe that the transition to these platforms is inevitable for forensics. The release of SWGDAM guidelines for MPS points to the fact that serious efforts are being made to deploy these platforms for day to day use. I suspect that MPS will become increasing routine over the course of the next five years.
What do you feel is the biggest challenge that forensics laboratories are facing today?
I’m not a forensic examiner, so it’s difficult for me to answer this question. However, one of the biggest issue that I see as an outside observer is that the field of forensic DNA analysis is increasingly being left behind and hasn’t really adjusted its thinking to “forensic genomic analysis”.
What do you think are likely to be the most exciting developments for the industry over the next couple of years?
The introduction of MPS is likely the most important development in human identification.
When you’re not at work, what do you most enjoy doing?
Fly fishing, skiing, and playing with my Siberian Huskies.
What tips would you give to someone who is just starting out in the forensics field, or what’s the best advice you’ve ever received?
Never stop learning. One of my rules in life is to learn at least one new thing a day.
How did you become interested in forensics?
I literally got a phone call from the Department of Defense and ended up giving a talk to the Defense Forensic Science Center. Prior to that, I just assumed what I was working on would only be a niche application in forensics.
For those who are on the fence about registering for the upcoming ISHI, please share your thoughts and reasons why they should attend.
Being new to the forensics community, I am looking forward to meeting people that are firmly established in the field and to learn more about the field in general.