An American white-tailed buck

CSE student combines physics with biology to tackle Chronic Wasting Disease

A new 24-hour test could make it easier to detect the disease

Peter Christenson likes to joke that he’s “a physics major working in an electrical engineering lab doing biochemistry.” That’s how interdisciplinary the College of Science and Engineering (CSE) graduate student’s research is—so much so that it recently earned him one of the University of Minnesota’s Interdisciplinary Doctoral Fellowships.

Christenson’s getting his Ph.D. in electrical engineering, but he earned his undergraduate degree in physics from Bethel University. Now, he is working in CSE Professor Sang-Hyun Oh’s Nanostructures and Biosensing Lab. He is also the recipient of two CSE donor-supported fellowships—the Dr. Steven K. Case Optics Fellowship and the Carl E. (EE 27) and Ethel A. Swanson Electrical Engineering Fellowship. In his work on the Twin Cities campus, Christenson uses facets of biology, chemistry, electrical engineering and physics to develop a faster, more efficient way to detect Chronic Wasting Disease (CWD).

Currently, the fatal neurological disease that affects species like deer, elk, and moose can take up to 14 days to detect.

Christenson was attracted to Oh’s research because of its biological applications. Although he has been surrounded by science since his childhood—his dad is a physicist—his interest in biology piqued during a summer undergraduate research internship in U of M College of Biological Sciences Professor Carrie Wilmot’s biochemistry lab.

“Seeing how unbelievably complicated and intricate biological systems are really fascinated me,” said Christenson, who received the Steven Case Optics Fellowship during his first two years on the Twin Cities campus. That’s what got me thinking that I wanted to work at the interface of technology and biology and see how we can use the cool stuff we know, in electrical engineering and physics, to see what applications we can find in biology.”

Good stewards of the land

However, Christenson hadn’t even heard about CWD until their lab was approached by Peter Larsen, an assistant Professor in the University’s Department of Veterinary and Biomedical Sciences, who was looking for collaborators to develop new tools to diagnose CWD.

Similar to Mad Cow Disease, CWD causes a build-up of “misfolded” or badly shaped proteins in the brains of deer and related animals, leading to nerve damage and, ultimately, death. The disease originated in Colorado, but has since spread to 26 states, including Wisconsin and Minnesota. The disease has far-reaching negative impacts for multiple economic sectors across the nation, from agriculture to deer hunting.

“There’s a fair amount of deer farmers around here whose livelihood is based on farming deer,” said Christenson, a Minnetonka, Minn. native. “And obviously the hunting economy is part of our cultural heritage that we want to preserve, and also for conservation purposes, we want to be good stewards of the resources that we have.

Whether we're hunting them or not, we want to try to keep our deer population healthy.”

One of the biggest barriers to controlling the spread of CWD is being able to detect it fast enough. Right now, one must extract lymph node tissues from a dead deer, and—for hunter-harvested deer—the DNR sends the samples to Colorado where they are tested in a lab. The whole process can take one to four weeks.

But, Christenson is working on a test that takes only 24 hours. His method uses a special solution that changes color in the presence of an infected deer tissue sample. While it may sound like more chemistry than electrical engineering, the technology actually leverages tiny nanoparticles, which are used in numerous fields including electrical engineering, chemistry, and physics. The unique properties of nanoparticles cause them to give off certain colors when exposed to different molecules.

“Since the test is quicker and simpler, we can do more widespread surveillance,” Christenson explained. “We could get a lot more samples looked at, and then the DNR could implement management strategies aimed at reducing the spread of the disease, strategies that are directly informed by expanded surveillance.”

Biology + technology

The researchers recently did a successful pilot run of the technology with the DNR in southeastern Minnesota, something Christenson said wouldn’t have been possible without the collaboration with Larsen’s veterinary sciences lab. 

“It’s really important that we have so many diverse studies here at the University of Minnesota,” he said. “If we didn't have a College of Veterinary Medicine, I wouldn't have thought to work on CWD.

I can learn molecular techniques in Dr. Larsen's lab while still studying and learning all these engineering techniques in Oh’s lab. For me, it's been really, really key in my development as a scientist,” Christenson said.

For Christenson, one benefit of working on this project is that it aligns perfectly with his desire to work at the interface of biology and technology, which is where he hopes to continue researching in the future. Above all, though, he said it feels great to have an impact on the place he calls home.

“I see how CWD is spreading throughout my state and how it impacts individual people's livelihoods,” Christenson said. “I have friends who own deer. I have friends who are hunters. When I talk to them, suddenly my science affects their lives, and they're really interested in talking with me about it. I’m learning stuff from them, and they’re learning stuff from me. I think in a lot of science, you are researching technology that will be used 15, 20, or 30 years down the road. I love how applicable this is now.”

Story by Olivia Hultgren

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