Identifying Non-Human Samples Found at a Crime Scene

Television shows like Dateline or Law & Order typically focus on identifying perpetrators through DNA found at the crime scene. But in reality, not every sample belongs to a human. Sometimes, samples may belong to household pets or even the meat you are cooking for dinner.

Mirna Ghemrawi, a student at Florida International University, shares one way that forensic analysts will soon be able to differentiate these samples as she presents her poster “Pyrosequencing Based DNA Analysis for Species ID” at the 30th International Symposium on Human Identification.





Travis: Good morning Mirna! How are you doing today?


Mirna: Good, how are you?


Travis: I’m doing great! I see that you brought a poster. Can you tell me a little bit about what you went for here in your study?


Mirna: So, this is a pyrosequencing study to identify species. We are trying to make it a quick and cheap method to see, like, if you don’t have a human sample, you want to know what the sample belongs to. What species exactly. So, we are focusing right now on household animals. So, your pets, the meat you eat, the type of fish you eat, and the human. And you can see on just one target, on the mitochondria, you see a very simple workflow. You can see those discriminating SNPs and differentiate those species across each other.


Travis: So, I love this. I’m wondering, who would be able to utilize something like this?


Mirna: So, in any crime scene, where you have a mixture, or you have a non-human biological evidence (any kind of biological). Could be blood, could be saliva, could be the hair of your pet, and you really want to know which one. Because it could be an important investigative lead, so you really want to see. And it goes, if you see here, in the sensitivity, it goes all the way to a very low quant. So, even from minute samples, because it’s a small target on the mitochondria, you can still be able to see and know which species it is.


Travis: This is fantastic. So, do you see in the future, could this become a marketable product?


Mirna: Well, that’s the aim, is actually to have it be implemented and be part as a kit in the market. So, forensic technologists can use it and can use it as a quick tool to actually be able to differentiate those species.


Travis: Wow, that’s great! So, after this poster, what’s your next big thing? What are you looking into now?


Mirna: So, we are still trying to finalize this. So, hopefully we publish it soon. So, then we can implement it into the market and then move onto another project.


Travis: That’s great, thank you so much. Have a great time with your poster here at ISHI.