Microplate handlers developed around the need to further automate liquid handling beyond its original function of dispensing fluids. “Integrating plate movement was a secondary feature,” says Eric Matthews, Midwest sales manager for BMG LABTECH (Chicago, IL). Today, robotics is central to integrating one or more devices with liquid handling.
Manufacturers have to some degree always taken a turnkey approach to designing automation systems, but today it is possible to design nearly any combination of components (handler, washer, reader) task-specifically or with built-in versatility.
This was due in no small part to the advent of inexpensive computing. “There was no true automation until PCs were capable of doing it,” Matthews says, comparing lab automation of 30 years ago to a drill press. “You’d put a plate into something, and it would do something to that place. There were no thermosensors, no scheduling, and everything required a lot of human intervention. If a plate was in the wrong spot or a pipettor wasn’t calibrated properly, users had to work it out themselves.”
Another innovation that changed plate handling was the availability of relatively inexpensive robots capable of fluid, three-axis movement and incorporating error detection and correction. “That ability, to move plates wherever you want, is a big deal,” Matthews says. “Like many other technologies, plate handling has followed Moore’s law.”
Spanning size, capabilities
Andreas Niewoehner, product manager for automated systems at PerkinElmer (Waltham, MA), breaks down the microplate automation market thus: small, benchtop systems; larger robotic systems; and full-scale, industrial robotic systems. For smaller systems, labs increasingly look for safe operation without the need for protection enclosures. “These are also easier to fit into tight lab space and integrate with other devices,” Niewoehner says.
Capabilities increase with size: Smaller systems may perform only one task, while larger automated workstations connect ten or more operations. “Users also expect a higher level of speed and robustness from these systems,” Niewoehner explains. “They were designed for production-like processes, such as pharmaceutical high-throughput screening, but are becoming popular in other industries.”
One problem with singleplate capacity plate handlers is that they create bottlenecks when one assay component is completed but the next one is not yet ready to accept the plate. An example might be a rapid agitation step followed by a ten-minute read. Employing two full-featured handlers or robots gets expensive. An alternative is “turntable” technologies that accept plates from the shaker. Turntables serve as workflow buffers, holding plates until the reader is ready. “The combination of articulated arm robotics and turntables can make a huge difference in terms of throughput,” Niewoehner notes.
The decision to automate is often based on throughput— number of plates processed per hour or per shift. But other factors enter the picture as well, such as plate read times and the anticipated level of human involvement in the process. A two-minute read of, say, 30 plates would require the operator to hover over the process for at least an hour, whereas a thirty-minute read affords meaningful time to attend to other duties between reads.
The value of automation also depends on the assay, says Kasia Proctor, product manager at Molecular Devices (Sunnyvale, CA). “The assay’s stability is critical. How stable is it [with] fluctuations in temperature or evaporation? Does it need to be in an incubator? Do you need to maintain a stable environment, or is the assay more flexible? Are your controls stable over the time frame of your process? You want to be sure that variations between plates are due to assay results and not to plate handling.”
Proctor differentiates between three automation options. A straightforward system based on a plate stacker adds and removes plates to one instrument, for example, a reader. At the next level of sophistication a small robotic arm may be employed to integrate three or four instruments (e.g., reader, washer, incubator). At the high end a full automation system involves several robots and multiple instruments or workflows.
“There are costs associated with fully automated systems, and the investment has to pay off at some point,” Proctor explains. Full automation therefore makes sense when labs anticipate running the same process(es) for long stretches. “You don’t want to build a whole room of automation for a month’s use or if you’re doing a little of this and a little of that,” she adds.
Consistency, operator time
Jason Meredith, product manager at Tecan (Männedorf, Switzerland), agrees that throughput issues most frequently trigger the automation of microplate processes but notes that consistency and freeing operator time may be just as valuable.
Automation suppliers can succeed today only if they account for human factors. “Robotics is not quite a commodity, but it’s close,” Meredith observes. “Robotics exists in many different workflows and is used by scientists and technicians who are not automation specialists.”
Prominent among usability factors are software and interface. “How many people know that their electronic gadgets have user manuals?” Meredith asks. “They do exist, but people find their way around the devices’ hundreds of functions without instructions. The same philosophy should apply to laboratory automation.”
Software plays a critical role in system versatility, allowing someone lacking extensive training to alter a protocol. “A user’s ability to set up new protocols reduces the need to call the manufacturer to adjust the robotics,” Meredith says. Some Tecan customers reconfigure on a daily basis, which is possible through the company’s open format automation systems. “Flexibility and usability increase the value of the automation component, improving its return on investment.”
Like many top vendors, Tecan configures systems to specific workflows. Flexibility is nevertheless highly desirable when projects end and instrumentation is reconfigured or when the same system serves more than one workflow. The company’s customers range from labs that perform highly repetitive assays to academic and drug discovery labs conducting a wide range of assays.
For additional resources on microplate handlers, including useful articles and a list of manufacturers, visit www.labmanager.com/microplate-tech