According to the team, the automated tests – that use numerous pinhead-sized magnets inside a handheld, all-in-one lab kit - can be easily manufactured, deployed and performed in surgeries, clinics or mass testing sites at the onset of a major infectious disease.
The technology breakthrough could help the authorities better prepare for future pandemics by decentralising testing and maximising the use of resources.
UCLA Samueli School of Engineering Professor Dino Di Carlo (bioengineering) and Associate Professor Sam Emaminejad (electrical and computer engineering) co-authored a study, which has been published in Nature.
The paper included findings from a clinical study with test samples from individuals who experienced COVID-19 symptoms. Over 100 test results using the lab kit were compared to the same samples tested for COVID-19 using polymerase chain reaction (PCR)-based molecular diagnostics performed as part of UCLA Health’s routine clinical care.
“Our handheld lab technology could help overcome some of the barriers of scarcity and access to tests, especially early in a pandemic, when it is most crucial to control disease spread,” Emaminejad said in a statement. “And beyond its potential to address issues of short supplies and high demand, it could be broadly adapted to test for many types of diseases in field and with lab-grade quality.”
Using a circuit board that controls movable, 1mm-sized magnetic discs called ferrobots to transport samples through the diagnostic workflow of a nucleic acid amplification test (NAAT), the researchers’ lab kit was able to detect the presence of genetic material from a virus. The steps to separate, sort, mix and amplify testing samples are all automated and performed at a miniaturised level inside the kit.
“This platform’s compact design and automated handling of samples enable easy implementations of pooled testing where you can test dozens of patient samples at the same time, and all with the same materials it currently takes to test just one patient,” said Di Carlo. “For example, you could test students in an entire college residence hall with just a few dozen test kits.”
By designing the kit for pooled testing, the system is said to require much lower amounts of reagent chemicals. Up to 16 samples were combined and tested simultaneously in the team’s study. If the pooled test showed a positive result, subsequent tests would automatically take place within the same platform until the actual positive samples were identified. This entire process took between 30 to 60 minutes, depending on whether there were positive samples. The technology’s assay miniaturisation and pooled-testing capabilities means that chemical reagent costs could be reduced by 10 to 300 times.
Aside from being able to test for several diseases simultaneously, the platform is also claimed to offer precision and robust automation. In a pooled-testing with 16 samples, over 300 lab operations, including mixing and sorting, were automated by the ferrobots, which equates to over 3,000 individual actuations. In their reliability studies, the researchers showed that the ferrobots could perform over eight million actuations without errors.
A patent application has been made through the UCLA Technology Development Group for the technology used in the new system.