One of RKT’s initial microfluidic projects was producing PCR test cartridges for a variety of rapid tests, particularly for multi-resistant germs (MRSA) and SARS-CoV-2. We supported Spindiag, a start-up, in the launch of full-scale production while establishing our own in-house expertise in toolmaking and injection molding of precise microstructures. The project involved all production steps of assembly, mounting, and packaging.
PCR Test Cartridges for a Start-Up
RKT’s Introduction to Microfluidics
RKT produced PCR test cartridges for detecting MRSA and SARS-CoV-2 pathogens under rigorous ISO class 7 clean-room conditions for a start-up client, automating nearly every step of the process.
PCR test cartridges are able to rapidly detect defined pathogens, quickly providing test results at the point of care without the delay of analysis by an outside laboratory. With RKT’s support, the start-up company innovated the PCR test for rapid detection of multi-resistant germs and succeeded in adapting the method to detect SARS-CoV-2 pathogens during the COVID-19 pandemic.
Designing a Sophisticated Assembly Process
When RKT partnered with the start-up, after the test cartridge’s core specifications, including microfluidic chambers, channels, and assembly sequence, had been established. RKT’s process engineers automated the manual processes done at Spindiag, scaling them up to high volume, with a high degree of automation under ISO class 7 clean-room conditions.
All from a Single Source
As the contract manufacturer for the project, RKT managed the entire value chain, including molding, assembly, mounting, and logistics. By taking responsibility for all these process steps, we gained extensive expertise in the production of microfluidic components and cartridges. This expertise enables us to provide other startups with a dependable path to full-scale production, a valuable capability as new businesses often lack the resources to manage these processes independently.
Process Know-How: Micropipetting, Lyophilizate Handling, Thermobonding
Micropipetting primer solutions involves precisely placing minuscule amounts of liquid onto individual microstructure chambers, which we achieved on an advanced automated production line. The liquid is then dried in an oven to enhance the cartridge’s durability.
The filled cartridges pass through a drying oven to evaporate liquids while drying the reagents to provide chemical stability.
Lyophilizates (freeze-dried reagents) are extremely brittle and hygroscopic and handling and loading them into the cartridges provided a unique challenge and maintaining precise temperature and humidity in our cleanroom was crucial. Stick packs—small aluminum bags containing liquids used for subsequent analysis —were affixed to the cartridge using UV adhesive. An advanced thermobonding technique to apply a sealing film to the cartridge was developed by RKT, requiring careful coordination of pressure, temperature, and time. Once the cover and sample input module were complete, each was loaded into atmospherically sealed primary packaging to protect each disk.
Avoiding Germs
Accidental introduction of particles or germs during the manufacturing process could negatively affect the PCR test results. To prevent any false-positive results, our employees were regularly tested for the pathogens MRSA and SARS-CoV-2 detected by the test kits.
Using collaborative robots improved the process flow and reduced the risk of contamination.
High Volume in Just a Few Months
Based on Spindiag manual process steps, RKT quickly set up a fully automated production line to manufacture PCT test cartridges in high volumes within a few months.
Sensor and camera testing: Fully automated camera inspection was used to ensure cartridges were filled and loaded properly.