Prokaryote playhouse: A low-cost, laser-cut acrylic incubator for optogenetic bacterial culture.

Bacterial photography is a printing technique that replaces conventional photochemistry with a living film of engineered Escherichia coli. Many biology teaching labs have adopted monochrome bacterial photography because it offers a captivating playground for illustrating central concepts and lab techniques in biological engineering, particularly in the fields of synthetic biology and optogenetics. Recent improvements have increased the number of color channels from one to three. A key practical challenge in three-color printing is to expose a Petri dish loaded with engineered bacteria to a trichromatic image while maintaining it at 37 °C. Prokaryote Playhouse is a compact, inexpensive, open-source, benchtop incubator for light-sensitive bacterial cultures that makes bacterial photography and similar bacterial optogenetic methods more accessible to teaching labs, makerspaces, and research labs. The system includes a laser-cut, light-tight enclosure; digital thermostat; heated sample shelf; single-board computer; and miniature projector. We built a fleet of Prokaryote Playhouses that students have used to produce hundreds of bacterial photographs in a wide range of educational experiences, ranging from a four-hour introduction to synthetic biology and wet lab techniques to a six-week exploratory class for first-year students at MIT.