Technical upgrade of an open-source liquid handler to support bacterial colony screening

Area of Science:

• Biotechnology
• Synthetic Biology
• Laboratory Automation

Background:

• High-throughput DNA assembly generates numerous genotypic variants for biotechnological applications.
• Screening these variants poses a significant workload for researchers.
• Commercial automated colony pickers are expensive, limiting access for smaller research institutions.

Purpose of the Study:

• To develop a cost-effective, automated colony picking solution for open-source liquid handlers.
• To enable smaller research labs to perform extensive screening of microbial colonies.
• To improve the efficiency of selecting candidate variants in genetic engineering.

Main Methods:

• Integration of a camera system with an Opentrons OT-2 open-source liquid handler.
• Development of software for automated colony detection, selection (based on size, color, fluorescence), and picking.
• Performance benchmarking using *E. coli* and *P. putida* colonies.

Main Results:

• COPICK achieved a raw picking performance of 82% over pickable colonies.
• Accuracy of colony picking was 73.4%.
• The system demonstrated an estimated picking rate of 240 colonies per hour.

Conclusions:

• COPICK provides a viable, automated solution for microbial colony picking.
• The system is compatible with open-source liquid handling platforms, reducing costs for researchers.
• This technical advancement supports smaller research teams in high-throughput screening for biotechnology.