Scientists Make Agar Art Accessible to Students

Agar can serve as a blank canvas. For roughly a century, scientists have used pigmented bacteria to create agar art, a practice credited to microbiologist Alexander Fleming’s early “germ paintings.” Since then, this type of art has decorated laboratory benches and has been celebrated through contests as a platform to showcase the wonderful world of microbes.

Still, as with many creative pursuits, the barrier to entry can be high. Agar art often requires specialized laboratory skills, equipment, or facilities to be done safely. Although there are commercialized kits on the market, Anne Madden, a microbiologist and founder of The Microbe Institute, wanted to make agar art even more accessible—particularly for teachers looking to bring it into classrooms or homes using materials found in a kitchen pantry.

In 2024, Madden, in partnership with a team of scientists and microbial artists, developed a simple protocol that relies on just a few materials: Kitchen Microbial Art. “The real thing that made this possible is the growth of mushroom cultivation and the supplies and kits around that,” she explained. As a result, people can order pre-poured sterile agar plates and create living paint from commercial baker’s yeast or sourdough starters. The latter was an unexpected success. Madden added, “One of the delightful aspects of this was that it didn't take a huge amount of trial and error, because I think that's kind of the beauty of the method—it's pretty robust.”

Yeast, Water, and an Agar Plate Make Microbial Art

The process itself is simple: People mix a packet of active dry yeast with tap water to create the paint, and then they can use a clean swab—such as a Q-tip—as the brush. They streak the invisible paint onto a Petri dish, tape up the plate, and leave it to incubate at room temperature for about 72 hours. As the yeast grows and consumes the agar, the image gradually appears.

In the fall of 2024, they put their agar art activity to the test and partnered with Gray-New Gloucester Middle School as part of Maine Bioscience Day, where members of the scientific community meet with students and showcase diverse career paths.

At first, Madden wasn’t sure how the sixth graders would respond. Some students had encountered yeast through baking at home, while others associated microbes with illness. But their reactions quickly dispelled any doubts. “They were so excited to dive in…Their enthusiasm was wonderful to see,” said Madden.

Part of what makes agar art unique is its invisibility at the start. Unlike traditional painting, where each brushstroke immediately appears, agar art requires artists to think ahead and abstractly. The paint can’t be seen at first, and the final image only emerges over time as the microbes grow. To help guide this process, the team gave students stencils to plan their designs. The students unleashed their creativity, designing images such as emojis, clocks, and animals.

After the event, Madden received thank-you cards from the students describing how they were surprised to learn that microbes could be beneficial and that now they had a new perception of microbes.

“A lot of instructors sometimes will ask, ‘How do we incite curiosity? How do we incite wonder in the world?’” said Madden. “I think this is an activity where if you give people the opportunity to play with microbes, it happens right away. It takes very little, and then you can just see the curiosity and wonder and excitement sort of grow along with the microbial art.” The activity also gives students a chance to become familiar with scientific materials. “Even just having that familiarity can break down barriers of seeing yourself as a scientist or seeing yourself in lab spaces, even if it's a classroom. And for a few dollars, that's priceless.”

Adults Can Be Agar Artists Too

This activity not only resonates with the sixth graders, but also adults. Coauthor, science artist, and fellow microbiologist Tracy Debenport led a workshop at the 2025 American Society for Virology Conference. The results were similar—adult researchers embraced the same creative spirit and produced intricate designs of bacteriophages, axolotls, and more.

Through this protocol, Madden hopes that agar artwork continues to resonate with broader audiences across all ages and backgrounds.¹ “At the end of the day, these [people] are going to be the next generation that go and discover the next amazing things in microbiology or act as guardians for our future. So, it's been really fun to work with instructors, scientists, artists to think about ways of increasing accessibility of tools, projects, and activities. I can't wait for the next collaboration that creates something like this.”