In 1971, scientists working independently in Sweden and the Netherlands published articles on the enzyme-linked immunosorbent assay (ELISA), which detects and quantifies a target protein in a sample. Usually detecting antigens, ELISAs can be developed as medical diagnostics or to reveal diseases in plants. Various processes in industry also use ELISAs for quality control. This technique, however, involves incubation and washing steps, which make it complicated to run lots of these assays at the same time. “Anytime you are manually processing more than four ELISA plates at once, it usually requires a robot to provide consistency,” says Rob Dunn-Dufault, product manager at Thermo Fisher Scientific in Waltham, Massachusetts. With a microplate handler, though, Dunn-Dufault has seen scientists run 200–500 ELISA plates.
The multiple steps and their required precision in ELISAs make these assays worth automating. “Immunoassays often require exact incubation times between each process step,” says Andreas Niewoehner, product manager for automated systems at PerkinElmer in Germany. “Using microplate handlers and automation in general, especially in combination with scheduling software, will help to ensure the correct and similar timing of all plates when running several plates in a batch.”
The technology for this is already available. “The current industry offerings are very capable of automating immunoassays,” says Michael Nguyen, principal scientist at Sanofi Pasteur VaxDesign in Orlando, Florida. “This provides several benefits over manual processes, such as higher throughput, better precision, and reduced labor hours.”
Despite such alluring benefits, some challenges exist. “The problem we most often face is translating these automated assays from the lab-automation engineers who develop them to the researchers who use them on a daily basis,” Nguyen says. “Because most prospective end users of our automation systems are not formally trained in their numerous components, user-system interaction can be challenging, which can lead to minimal acceptance and even avoidance of the technology.” Therefore, getting the benefits of automating these assays depends on starting with the right approach.
When asked what problem most commonly arises, Nguyen says, “With regard to microplate handlers specifically, we have very few technical problems when using them to automate immunoassays.” He adds, “In fact, we use robotic arms that are more than ten years old on several of our automation lines, and they are very reliable and low maintenance.” Nguyen and his colleagues also use “microplate stackers with various plate readers and washers with minimal issues.” The problem for Nguyen comes mostly from discontinued support of a specific robotic platform.
If the vendor stops supporting a microplate handler, a user will eventually need to replace it and revise the automated assays as needed. “This can happen sooner than expected, with the rapid pace at which the technology evolves,” Nguyen says. Older microplate handlers can also cause trouble when they don’t integrate with newer equipment being used in the assay.
To keep a system optimized, the scientists must stay up to date. “It is important to stay informed of the current and upcoming technology by attending lab automation trade shows, routinely browsing literature, and maintaining our vendor contacts,” Nguyen says.
Simplifying the steps
In some immunoassays, scientists want to move plates and control their environment between moves, which can be done with BioTek’s BioSpa 8 Automated Incubator. “It can send plates to liquid dispensing and then back to the incubator, followed by further liquid handling, imaging, or detection processes,” says Lenore Buehrer, product manager at BioTek Instruments in Winooski, Vermont. This instrument manages up to eight microplates and a variety of other vessels. “It alleviates the need to have multiple instruments for handling and incubation,” she adds. A user just puts the plates in the BioSpa 8’s drawer, and then the scheduling software takes over for unattended operation.
To make it even easier to automate microplate handling, Thermo Fisher Scientific uses machine vision in its Spinnaker Microplate Robot. Product manager Dean Mulyk explains: “It uses machine vision to validate instrument locations to look for any anomalies before users commit their precious samples to the system.” He adds, “Our solutions include on-site installation and training, which allows users to create or tweak their ELISA processes.” All Thermo Fisher platforms, Mulyk points out, include easy-to-use intuitive software that users can employ to build and execute their ELISA processes.
Overall, improvements in the software can matter the most. “Most innovation in the past few years was geared toward improving the scheduling software—such as PerkinElmer’s plate::works™ automation control and scheduling software—to make the setup processes easier, faster, and more flexible to adapt to new applications,” says Niewoehner.
Getting the right system
The automation of an immunoassay requires thinking about how to fit in the robotics. “Microplate handlers are a core component of a lab automation setup and dictate important aspects such as footprint, device integration capability, and choice of scheduling software,” Nguyen explains. “We carefully consider these factors when designing upgrade paths for legacy devices, taking into account the impact on current and future assays and potential for longterm success.”
In considering a purchase, look for what fills all of your needs. Nguyen says, “Because it is not practical to provide extensive training for most of our end users, we implement interfaces that provide a layer of separation between users and the automation systems.” This layer automates things like entering metadata or loading labware. “Often, we find that commercial options for these types of interfaces are lacking or do not fully meet our needs, and we resort to developing in-house solutions to fill the gaps,” Nguyen says. “While this approach has contributed to the successful adoption of automation by our researchers, it also creates an additional workload for our automation engineers in terms of code development and maintenance, and we continue to shop for off-the-shelf solutions when considering next-generation systems.”
So it pays to shop around to automate things the way you want them to be. With the range of options, most scientists can find something that fits many—if not all—of their needs in automating immunoassays.
How to Automate Your Lab on a Budget
Getting the most from automation depends largely on the specific application. Nonetheless, some general planning helps in almost any approach to automating a lab process.
For additional resources on Microplate Handlers, including useful articles and a list of manufacturers, visit LabManager.com/microplate-tech