Automated colony-picking instruments have been used for many years to image and select “good” bacterial colonies from an agar plate, pick the good colonies with a pin, then inoculate a microplate filled with media. The pins were then sterilized and the process was repeated. Colony- picking instruments had to be fast, robust, and able to pick tens of thousands of bacterial colonies per day. Flexibility, however, typically ended at distinguishing blue from white. Today’s colony picking instruments, on the other hand, are integrated solutions of process software, control software, and hardware.
Current colony-picking instruments are flexible with advanced software features for picking from segmented plates and customized reporting functions. While genomic and proteomic labs still use bacteria as a medium for growing and isolating their samples, the need to pick thousands of colonies from the same library is not as common. Most labs are moving to smaller libraries with fewer samples picked from a more diverse pool. While fewer samples are being picked, there are more and more plates to pick from, and samples must be organized and tracked in a consistent manner. The challenge has shifted from increasing throughput of picks per hour to throughput of plates and picks. Plate handling and tracking are as important as good imaging of the colony plate.
Automated colony-picking systems must be flexible enough to let the user set up a run picking a certain number of colonies and placing them in a specific order in the destination plate. Barcode readers that automatically read the barcode on the plates allow the user to set up complex runs, and alert the system to any loading or reading errors.
Dual inoculation is a requirement for many labs. The pin with bacteria inoculates the microplate with media for growth, and then inoculates a PCR plate. The PCR plate is then processed while the colonies are grown in an incubator.
Automated colony-picking instruments are process focused. Automated runs should handle shallow- or deep-well plates and provide the ability for multiple hours of walk-away time. The system software should alert the user when the run is completed or if there is an error like a misread barcode. The colony-picking instrument should be available with multiple options to help the user customize the core instrument to their particular needs.
Colony-picking solutions from Hudson Robotics include the RapidPick, RapidPick Lite, and RapidPick Complete. The systems are customizable and can pick more than 200 colonies per hour.