PrintrLab incubator: A portable and low-cost CO(2) incubator based on an open-source 3D printer architecture

Growth in open-source hardware designs combined with the decreasing cost of high-quality 3D printers have supported a resurgence of in-house custom lab equipment development. Herein, we describe a low-cost (< $400), open-source CO(2) incubator. The system is comprised of a Raspberry Pi computer connected to a 3D printer controller board that has controls for a CO(2) sensor, solenoid valve, heater, and thermistors. CO(2) is supplied through the sublimation of dry ice stored inside a thermos to create a sustained 5% CO(2) supply. The unit is controlled via G-Code commands sent by the Raspberry Pi to the controller board. In addition, we built a custom software application for remote control and used the open-source Grafana dashboard for remote monitoring. Our data show that we can maintain consistent CO(2) and temperature levels for over three days without manual interruption. The results from our culture plates and real-time PCR indicate that our incubator performed equally well when compared to a much more expensive commercial CO(2) incubator. We have also demonstrated that the antibiotic susceptibility assay can be performed in this low-cost CO(2) incubator. Our work also indicates that the system can be connected to incubator chambers of various chamber volumes.