To help students “see” the how the immune system works, Dr. Erica Suchman enlisted the help of two honors students and a 3-D printer.
Professor of Microbiology, Colorado State University in Fort Collins
PhD in Molecular Biology and Biochemistry, BA in Biology
“Everyone knows somebody who has a virus,” says Erica Suchman, PhD, who teaches microbiology at Colorado State University’s College of Veterinary Medicine and Biomedical Sciences. But not everybody understands how viruses (and antibodies) work—and that includes students in her undergraduate General Microbiology course.
There, among other things, Suchman is tasked with teaching students about antigens, epitopes, and antibodies. Though many students know that antibodies are proteins in the blood that the body produces in response to an invader, only a few know that the invader contains antigens. And most have never even heard of epitopes, which are the parts of antigen molecules to which antibodies attach themselves. (This triggers a chain reaction to destroy the antigen.)
“Students have a really hard time grasping the difference between an antigen and an epitope,” Suchman says. This makes it difficult for them to visualize antigen-epitope interactions. (Epitopes are portions of antigens that antibodies bind to only in very specific ways—like two pieces of a puzzle clicking together.)
At first, Suchman tried to demonstrate these relationships by having students draw pictures, but they still did not fully grasp the concept, she said. Then she happened upon the idea of using a 3-D printer to create models of antigens, antibodies, and epitopes, which students could observe and manipulate.
Below, she shares how she had the models created—and how she uses them in her classroom to teach about influenza, cloning, and more.
See resources shared by Erica Suchman, PhDSee materials
“Before we started using 3-D printed models to teach about epitopes and antibodies, the students clearly didn’t ‘get’ how they work. Then we added the models, and they got it. They love the models.”— Erica Suchman, PhD
Course description: Structure, function, development, physiology, and molecular biology of microorganisms emphasizing bacteria.
Lesson: Using 3-D printed kits to get hands-on with the microscopic world
Suchman says that it took about six months for the original 3-D models of antibodies and epitopes to be designed and printed. Suchman did not create them herself but instead partnered with a pair of honors students—one a microbiology major and the other a computer science student—who created a model of the influenza virus as their honors thesis project, using a free app called Tinkercad.
The influenza virus, says Suchman, is a good one for students to study because it has two major antigens on it, and each of the antigens has multiple epitopes. After printing out the completed models, magnets were glued to the pieces so they could be attached to each other in various ways.
Below, Suchman shares some insights into her use of these 3-D models to teach microbiology:
Introduce concepts via 2-D videos before sharing 3-D models
Before working with models, students watch an antigen-epitope lesson on video as homework. In the next class session, Suchman delivers brief directions and explanations. Through all of this, students learn that antibody variable regions are coded by gene fragments that randomly reassort and mutate to generate a vast number of different proteins and specificities. Some bind to specific epitopes or patterns of epitopes, and some do not.
Links to Suchman’s 3-D Plans (and Research)
Suchman has made the files for her 3-D models available for free on MakerBot’s Thingiverse—a site where educators can share 3-D printable designs to download and print. (There are currently more than 1.6 million!) Her resources include:
- Antibody Epitope teaching kit
- Cloning vector/insert kit to demonstrate how restriction enzymes influence insert cloning direction
For a more detailed explanation of this approach, read Suchman’s coauthored article “Modeling Antibody-Epitope Interactions with 3-D Printed Kits in Large or Small Lecture Courses,” which appeared in HAPS Educator: Journal of the Human Anatomy and Physiology Society, April 2018, pages 73–78.
Let students use the 3-D models make their own connections
Next, Suchman distributes the 3-D model kits, and the students “play around” with the models to figure out what epitope each antibody will bind to. Students discover that some of the variable regions will not bind to any epitopes, and some of the regions will bind to different epitopes. In this way, Suchman says, “they can see how the immune system is actually working.”
Have students record their observations on a 2-D drawing
As they manipulate the models, students also complete worksheets that include pictures of the models, which students label to identify certain parts and where they connect.
Use a clicker quiz to check for understanding
After the worksheets are completed, Suchman gives students a clicker quiz to make sure they understand the lesson. The most recent quiz results show that students understand a great deal more when they use 3-D models than they did with just lectures and drawings.
Adapt the models (or create new ones) to explore other concepts
Suchman says that the antigen-epitope models can be used—with additional pieces—to explain concepts such as isotypes, cross-linking, and neutralization. She has also developed 3-D models to teach cloning—particularly the way that plasmids and DNA inserts work.