Microplate handlers are specialized robotic devices that transfer microtiter plates in three-dimensional space from one location within a workflow to another. The “locations” are actually operations such as solvent addition (through liquid handling), aspiration, heating, shaking, incubation, washing, reading, and storage.
Plate handlers are common in laboratories that process hundreds or thousands of microplates per week, for example, high-throughput screening labs in the life science and pharmaceutical industries. Most plate handlers are used in life science industries, particularly pharmaceuticals and biotech.
One can make the case for incorporating some type of robotic handler even for low-volume labs. Unfortunately, cost and complexity frighten off many potential users.
Microplate handlers are indeed the “glue” that binds mission-critical microplate applications. Their value accrues from accurate, timely, unattended plate transfer that frees lab workers to perform more complex analytical tasks such as secondary screens. Many users acquire microplate handlers for speed, but their greatest benefits are the abilities to standardize microplate operations and workflows, provide greater consistency, decrease the chance of error, and track every operation that plates undergo.
It’s all in the workflow
Early microplate handlers were clumsy devices borrowed from the world of industrial robotics. “They could hold microplates, but were not designed for that purpose. They were overkill,” notes Todd Christian, head of global marketing for automation solutions at Agilent (Santa Clara, CA). Today’s handlers are better-suited to their delicate task.
Plate handlers are part of what Alisa Jackson, marketing manager for genomic chemistries and Biomek consumables at Beckman Coulter (Brea, CA) calls “workflow solutions” intimately tied into application needs. Robotics allow users to modify and create custom workflows; for example, the user may insert a new step such as centrifugation, adding buffer, and transferring the plate to the next operation. How smoothly the process runs depends mostly on how well end users understand their workflow.
“That’s the first place to start,” Ms. Jackson says. Users need to understand how movement affects each operation, how often plates need to be moved (and to what degree the operators care to move them manually). Sometimes plates need to be transferred to a location that is off the “deck,” to an operation that has not yet been, or cannot be, integrated physically into the workflow.
Traditional plate handlers move plates in 3-D space, but they are expensive and can be difficult to program. Jackson mentioned two other automation tools that can augment robotic handlers, perhaps reduce some of the complexity of workflow automation, and help utilize all available space. The first are labware shuttles (also known as conveyors), which move plates horizontally. Conveyors may be belt-driven or incorporate a sealed magnetic transport mechanism. Shuttles move plates horizontally by fully supporting the plate from below. Some operations, like pipetting, may occur on the shuttle itself. The second tool is an elevator, which can help optimize the work area in the vertical dimension.
“With lab space at a premium, users need to make the most of vertical space,” Mr. Christian says, “using less benchtop space for the same workflow.”
Laboratory robotics are not as intuitive as other labware and provide value only within a context of other instruments. That is why most vendors emphasize support for microplate handler sales both before and after the purchase, particularly in workflow analysis and setup. They also emphasize software and user interfaces in an effort to flatten the learning curve and allow more end users to fully exploit the robot’s functions.
As with any instrument, power users who write code or macros will always exist—but automation companies need to placate users at both ends of the expertise spectrum. “You don’t want the usability of your instrument to be limited to the super-user,” says Kasia Proctor, product manager at Molecular Devices (Sunnyvale, CA). “We want anyone to be able to walk up and do what they need to do.”
Molecular Devices sells microplate readers, washers, and stackers and integrates its instruments with plate handlers and other microplate “operations” from the likes of Agilent, Beckman Coulter, and Thermo Fisher. “It depends on what the customer wants, and what they already have,” Ms. Proctor observes. Users may already own a washer and reader connected by a simple pick-and-place robot and require a different reader, or liquid handling, or both. Generally speaking, users should be able to swap out a reader or washer without calling in a service team. It gets much more complex when multiple functions are added to an existing workflow and, depending on the level of automation desired, the robotics may require upgrading as well.
The level of support required to set up a microplate workflow that includes plate handling depends on how attached customers are to the components they already own and on the level of in-house expertise. Some customers still create their own homebrewed systems, picking and choosing among components from different vendors—often legacy instruments from times when these instruments were operated in full manual mode.
“But as automation moves into newer areas, integration becomes more important,” observes Agilent’s Mr. Christian. Components need not specifically require seamless interoperability; however, a versatile plate handler run through a user-friendly interface can smooth over many of the workflow disconnects between company A’s microplate storage “hotel” and company B’s shaker.