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Tutorials : Nov 1, 2011 (Vol. 31, No. 19)

Gene Cloning and Colony Picking

Integration of Picker on Liquid-Handling Platform Increases Production of Clones
  • Tamara Brown, Ph.D.

Colony picking is a very labor-intensive task that is generally performed during cloning protocols, alongside additional upstream and downstream processes. Manual colony picking is both slow and tedious. Automation makes the process more consistent and reliable, as well as considerably faster, enabling thousands of colonies to be picked per hour.

Until recently, the only available industrial colony pickers were single-task and high-cost standalone instruments, and in many laboratories colony picking was not integrated with upstream or downstream automation systems. This resulted in periods of low productivity, when laboratory staff was waiting for a procedure to finish.

The introduction of integrated colony pickers on liquid-handling platforms has revolutionized gene cloning and colony picking workflows in the laboratory, allowing time­-efficient and error-free cloning processes and increasing the annual production of clones.

Tecan and SciRobotics have joined forces to create just such a system, a colony picker integrated onto a liquid-handling platform.

SciRobotics’ Pickolo™ colony picker—a bacteria colony-picking solution capable of automated picking of up to 800 colonies per hour—can be quickly and easily installed onto Tecan Freedom EVO® liquid-handling platforms (Figure). The Pickolo’s software is fully interfaced with Tecan’s Freedom EVOware® software to create a cost-effective, off­-the-shelf solution.

High-resolution digital-imaging technology and flexible, easy-to-use analysis software allow individual colonies to be selected based on user-defined criteria—including size, shape, and color—and can be extended to fluorescence-based applications with the addition of a Tecan detection instrument.

Fully Automated Cloning Workflow

Evogene, which develops improved plants for the agriculture and biofuel industries through the use of plant genomics, has integrated SciRobotics’ Pickolo colony picker onto Tecan’s Freedom EVO 150 workstation to establish a fully automated cloning workflow. Based in Rehovot, Israel, the company provides a complete solution for improving plant traits, such as yield or drought tolerance, using advanced breeding methods and its own computational genomic technology.

The process of discovering and targeting new plant traits involves a range of technologies, including high-throughput plant validation systems, field experiments, and genomic data creation. A key procedure is the cloning and amplification of several hundreds of genes of interest in a limited time span, which are then passed to the plant transformation unit for transformation into a model plant.

Alleviating the Bottleneck

Many of the steps involved at this stage, such as PCR amplification, DNA restriction and ligation, clone screening, and sequencing, require specific clone design and a different set of restriction enzymes, as well as different sets of unique primers. Such procedures need to be handled with the greatest attention to detail; the success of every step in the process needs to be tracked and all the intermediate products need validation.

This meant that a standalone picker performing only a single task would not be able to handle the workload; an automated process was required. Evogene’s Freedom EVO 150 system was configured with an eight-channel liquid-handling arm with a Te-Shake™ shaker, a Te-VacS™ vacuum separation module, and SciRobotics’ integrated Pickolo colony picker, which now performs 13 different automated processes for the laboratory (Table).

An Efficient and Reliable Workflow

Prior to integrating the Pickolo colony picker onto the Freedom EVO workstation, colony picking and PCR screening involved very intense, focused days, with scientists at Evogene dependent on assistance from laboratory staff engaged on other projects. By adopting an automated colony-picking procedure on the Freedom EVO platform, it has been possible to reduce staffing levels to one person. Additionally, the process now takes just a few hours, leaving enough time for downstream processing and parallel activities to be performed.

The integration of SciRobotics’ Pickolo colony picker onto the Freedom EVO workstation enables laboratories to handle any subset of clones and perform time-consuming procedures with both flexibility and speed. The system allows for dependable tracking of cloning processes and ensures an efficient and reliable cloning workflow.