What does it take to extract truth from the past—when all that remains are fragile bones buried for decades?
In this interview, former ISHI Student Ambassador Ahana Chatterjee sits down with Dr. Maria Saiz Guinaldo, a forensic biologist and postdoc investigator at the University of Granada, to discuss her work identifying human remains from the Spanish Civil War.
You’ll hear:
- The technical obstacles of degraded bone samples
- Pretreatment methods to reduce contamination
- The emotional impact of identification
- How IGG could shape the future of historical casework
- A deeply personal case that redefined what this work means
Whether you’re in the lab or the classroom, this conversation is a reminder of why we do this work—and what’s at stake when we do it well.
Transcript
Ahana: I’m Ahana and I am doing my doctoral studies at Sam Houston State University in forensic science. And I’m your student ambassador at ISHI this year. With me, I have this beautiful lady who is a scientist. So, scientists can be beautiful too. Why don’t you introduce yourself?
Maria: Hi, I’m Maria and I come from Spain, from the University of Granada. I have a PhD in biology, and I’m also a postdoc investigator at the laboratory of Human Identification of the University of Granada.
Ahana: Which is beautiful also, FYI. She knows how to live life. She is full of life, and we already have that vibe in the room. So, let’s dive deep. And my first question to you is what made you interested in this field of forensics? Because, you know, this is not something that everyone decides to do in life.
Maria: When I was starting my degree in biology. Last year, we had some lessons with expertise in the forensic genetic field. And, when I was listening to him, I said, I want to do that. That is what I want to do in my life. And that’s when I just decided to try it and to go to Granada, where I live and where I work at. And that’s it. 15 years before I started working with forensic genetics. And I love it.
Ahana: There you go. Forensics is amazing. More people should do it. So, you work with degraded human remains, right? So, tell us some more about all the challenges that you face when it comes to this sample type. Because this is one of the hardest sample types to work with. So why don’t you share with us some of the challenges?
Maria: Well, it’s true. It’s really, really hard to work with them. And also, our project, our samples come from the Spanish Civil War, which have more or less 80 years.
Ahana: Yes.
Maria: So, we also have the handicap not to work with human bones, but to work with human bones that have been buried in the in the field. They have suffered from the weather, from rain. So, it’s really hard to work with them. And we are always working on trying to fight against these challenges. We get to work with them.
Ahana: Right? It’s very, very difficult. And I have just started working with bones. So even with fresh bones, I’m like, wow, this is this is intense. But you work with such degraded ones, so it’s I’m sure harder. That’s going to be a part of my dissertation. We will be working with degraded bone samples, so hopefully we can talk more about it. Not while we are doing the interview. So, you said you have a lot of challenges, right, with the sample types, but can you, like, give us some of the things you do to overcome the challenges and work with the samples?
Maria: Oh, okay. The first thing we do in the lab, which I think is very important part, although a lot of people don’t think about it, it’s a pretreatment of the human bone to eliminate the all the outside of the bone so we can get off the most possible contaminants that are in this bone.
Ahana: Yes.
Maria: Also, we work with quite good inhibitor removals. Right? And also with the purification steps to remove these inhibitors. But also we work with amplification kits that include quality sensors. So, we can see the possible inhibitors. So, we cannot give negative results. False negative results. So, when we give a negative profile, we know that it’s really a negative profile. Not that it’s a profile that has inhibitors. And we cannot really see that profile.
Ahana: Got you. That is a great answer. So, like you said, you guys work with Spanish Civil War samples, right? So, my question is, I’m sure you use STR typing as one of your methods. Do you think IGG will be something that you guys will try with your samples at any point?
Maria: Yeah, but it’s a future we want to explore because we have a lot of, as I said, there are 80 years more or less. So, another challenge we have to focus on, we have to fight against are the relatives we work with. There are little few sons, there are little daughters, there are little few siblings. We have a lot of grandchildren. Great grandchildren. Nieces, nephews. So, the relationships are distant and it’s more difficult to get information with the autosomal STRs and to give identification. We also use a lot of lineage markers like mitochondrial DNA, Y chromosome, X chromosome. But for sure IGG will be the future. To explore, to use it with our bones and to try to give more identifications.
Ahana: That’s amazing. And I’m sure the number of workshops and talks we’ve heard here at ISHI this year, there were so many talks about IGG, which I think helped all of us to just understand the process better and hopefully one day IGG will be our solution. Is there a particular case that you worked on that has stuck with you or anything related to one specific case. It might be the most challenging one or the most rewarding one.
Maria: Well, we have all our cases and not only our cases, but all our identifications are very rewarding. And are with us. But we have one recently that they told us that the son of the victim was very ill and was about to die. We hurried up with the bones and we really identified his father. And then after they gave him (this man) the bones of his father, he died three days later.
Ahana: Oh, my God, that is so wholesome. That’s beautiful. This is why we do forensics. It’s moments like that. That’s great. I have one last question for you. And this is going to be a general question. So, I am a forensic science student, and I’m sure there will be a lot of students who are going to watch this interview who are in the forensic field. So, do you have any advice or a suggestion for anyone who wants to take this up as a profession?
Maria: I would tell them to keep on. Yeah, keep on working. Keep on fighting for their dreams. If they really want to work in the forensic field, just don’t give it up.
Ahana: Yeah, I love that, love that, love that. I’m going to keep that in mind on days when I’m questioning my decisions and I’m like, why am I doing this? But thank you so much. Thank you for deciding to do this with us.
