Open-source cell culture automation system with integrated cell counting for passaging microplate cultures

Tissue culture in 96-well microplates is conventionally a tedious, highly manual process subject to human error and sensitive to individual technique. Here, we describe the Automated Cell Culture Splitter (ACCS), a versatile and low-cost system for passaging plates of adherent or suspension cells, for routine culture maintenance or more specialized downstream applications such as seeding plates for microscopy. The system is built around the Opentrons OT-2 liquid handling robot and incorporates a novel on-deck imaging-based cell counting instrument which allows it to compensate for density disparities across a source plate and control the number of cells seeded on a per-well basis. We find this solution compares favorably to our existing manual cell culture processes in terms of both accuracy and biological out-comes while cutting the hands-on time required per plate by more than half. The system is designed to be readily adaptable, and we anticipate that it could find uses in a variety of scenarios as an accessible entry point into automation for high-throughput cell culture; to that end, all of the source code and hardware designs are released under open source licenses.