A New Way to Determine Body Fluid Type from Crime Scene Samples

Joana Antunes of Florida International University describes how forensic laboratories may soon be able to use methylation markers in DNA to determine body fluid type without destroying the sample collected.






Hi, my name is Joana Antunes. I am a Ph.D. student at Dr. Bruce McCord’s research lab at Florida International University. The reason why I started studying forensics is because I’ve always liked science, and I’ve always been involved with science. And then I liked the practical aspect of forensic sciences, so I decided to enroll in a Ph.D. program here in the United States.

So, my poster is about body fluid identification using DNA markers – methylation markers in the DNA. This particular project was very interesting to me, because it combines almost a fundamental type of research in biochemistry (which has been my background so far), and also the practical application of that research.

In certain forensic cases, we need more than just a match of the suspect to the crime scene. We also need to determine the involvement of the suspect in such crime scene. For those particular cases, we need to determine with accuracy the type of body fluid that was found.

We currently collect samples from a crime scene, and from those samples (depending on what it is), we may do tests to determine body fluid. But the issue is that those tests are going to destroy that part of the sample. In the future, we will be able to just collect the entire sample, extract the DNA from it (to match a suspect to a crime scene), and then from part of that DNA extracted (which will now be in a tube that will be easy to store; it can be stored and stable for several years) we will be able to later just take a little bit of that DNA liquid and determine the body fluid.

It’s very advantageous, because the DNA extraction validation and everything is already established in forensic laboratories. We’ll be able to get one sample with two purposes. Matching the suspect with the crime scene, and determining the type of body fluid. Hopefully, we’ll be able to see in forensic laboratories all over the world soon.