by Caitlin Smith
Stack your microplates, press a button, and walk away—and upon your return, reams of new data await you. Automation of microplate handling and processing has made this a reality for many labs.
But total automation isn’t necessarily a good thing—not when it supplants flexibility, that is. Phil Farrelly, president of Hudson Control Group, notes that it’s important to be able “to access instruments for occasional manual use or automated use of only a small portion of a large workcell.” For example, Hudson’s system allows researchers to orient the instruments to face the user rather than the robot. “This opens every instrument up to easy manual use (when perhaps only a few plates are being processed) and easy access for maintenance,” says Farrelly. “Users need not resign themselves to only those processes that have been pre-taught and tested with the robot arm.” The good news is that flexibility and high-throughput automation of microplate processing are now going hand-in-hand.
Plates in the right place, at the right time
Robotic technology is easing and speeding the movement of microplates, allowing researchers to design ever more complex and accurate plate protocols. Hudson Control Group uses a track-based plate movement system called LabLinx. It “incorporates a unique stacker that will feed tens of thousands of plates without a misfeed,” says Farrelly. “It employs a unique plate gripper that actively grips the plate at the bottom of its stack and pulls it down to the track level, allowing the mechanism that keeps the next plate from dropping down with it to have a huge safety-factor in closing the opening the plates must descend through. This permits our stacker, the StackLink, to offer a reliability that simply isn't available from everyone else's gravity-fed stackers.” Hudson’s ArmLink is another component of their LabLinx system. A “pick-and-place” robotic arm, it moves plates from the LabLinx track into other instrument “nests.”
Hudson’s LabLinx can also link up microplate transportation to other types of robots. “Our liquid handling products are all designed so that they will operate on a plate located on a LabLinx track, so that the user never needs to use a robot arm to lift and position a plate for processing,” says Farrelly. “The LabLinx track also does the same thing for most other vendors' liquid-handling robots (such as Beckman's NX, or PerkinElmer's Janus), permitting them to be integrated into a track system that eliminates the need to lift and place plates on their decks.” This unique system “dramatically improves throughput and decreases plate-handling mishaps,” notes Farrelly.
BioTek offers its BioStack™ Microplate Stacker with Rotational Wrist that is compatible with BioTek’s products as well as some other vendors’ instruments, according to Jason Greene, product manager at BioTek. “The BioStack's integrated rotational wrist allows users to integrate both landscape and portrait orientation microplate carriers,” says Greene. “In addition, new 50-microplate storage stacks or the originally designed 30-microplate stacks may be selected to accommodate individual throughput needs.” Greene adds that microplate stackers are becoming smaller, yet simultaneously more versatile. “With bench top space being so precious in most laboratories, a small footprint is at the top of the priority list with new product development,” says Greene, adding that “the BioStack Microplate Stacker is modular in design for repurposing when automation needs change, and now more flexible with integration and throughput options.”
Scheduling for smoother handling
An exciting development in microplate handling, according to Farrelly, is the ability to use all of a system at any given time. “Most automated assays only use a portion of the system's capacity at any given time,” explains Farrelly. “Often, valuable instruments are left idle simply because a long-running process doesn't need them at a particular stage of the process. Why not let other users step in and start another process even while the other is running?” Unfortunately, for many schedulers this isn’t possible—either because they weren’t designed to run asynchronous processes, or “because they can't resolve inevitable motion conflicts that will ‘lock’ the system up, stranding plates in positions that cannot be resolved,” says Farrelly. To solve this conundrum, Hudson’s SoftLinx workcell scheduler features a unique “system router” that can calculate paths for any plate to travel along between any two points in the system. It “even moves interfering plates out of the way to let a plate pass through its position, then moves it back when done,” says Farrelly. “This tool completely eliminates system lock-ups. This opens any system that uses SoftLinx to far more usefulness than ever before, as even short processes are now efficiently handled and valuable instruments can get full-time use instead of being idle so much of the time.”
Teach your robot well
For applications like drug target discovery or drug screening, more plates processed per day means drugs traveling to market faster. “Our customers are truly challenged with getting quality leads into their development pipeline,” says Marc Beban, director of integrated systems and software marketing at Agilent Automation Solutions. “They need technology that is reliable and our direct drive technology means fewer moving parts to break down so that they can have the confidence they need to focus on the science, not the machinery.”
Agilent Automation Solutions recently released their Direct Drive Robot (DDR), whose sole purpose is to move microplates. “It is the centerpiece of our high-end automation platforms where our customers are processing hundreds or thousands of plates in a single run,” says Beban. “It is the key technology in our customers’ drive to fill their pipelines more efficiently—faster and with high quality leads. The Direct Drive Robot uses configurable Z-travel technology to enable greater stacking of instruments and more functionality in a smaller footprint.” DDR comes with greater ease-of-use, too, in that it is designed to learn from you how to move. “By placing the robot in teach mode, and holding the teaching jig, the unit can be manually placed at the point to be taught and a button on the end effector touched, thus teaching that position,” says Beban. “There is no need to use a pendent to job the arm into position—therefore less time is spent on repositioning and refining.”
Another version of robotic teaching is integrated into Hudson Control Group’s PlateCrane EX with its Vision Teaching option. The PlateCrane EX has a camera mounted inside its gripper that lets you position the robotic arm in the exact position of a plate. “An entire workcell can be taught with unparalleled accuracy in roughly five to 10 minutes,” says Farrelly. “This is ideal for the user who occasionally wishes to add new instruments or movements to the workcell. The teaching process is entirely screen-prompted, requiring no practice or study by the user. Anyone can master it immediately upon first use.”
Potential roadblocks
Despite advances in robotics, microplate processing still faces potential roadblocks. For example, says Greene, not enough users know about microplate standards. “Customers are oftentimes not aware, complete their assay development with a specific microplate, and then are surprised when their microplate handler has issues when it comes time to automate,” says Greene. Whether you’re looking to automate routine tasks or to step up your high-throughput work, automation of microplate handling is continuing to evolve to keep your work running smoothly.