The project aimed to deliver a rapid point‑of‑care (POC) diagnostic system that can distinguish SARS‑CoV‑2 from other respiratory pathogens and simultaneously quantify C‑reactive protein (CRP) as an inflammation marker. The work was carried out as a subproject of the German company Spindiag and the HSG laboratory, with clinical validation performed in collaboration with the University Hospital Freiburg (UKF). The overall goal was to provide results in less than one hour, with a target turnaround time (TAT) of 30 minutes or less.

Technically, the system combines centrifugal microfluidics with real‑time PCR. A disposable cartridge, referred to as the Rhonda‑COVIRES cartridge, contains all reagents needed for sample lysis, nucleic‑acid extraction, reverse transcription, and multiplex PCR. The design allows the device to process a swab sample and a blood sample for CRP in a single run without the need for laboratory personnel. Spindiag already markets three CE‑marked products—Rhonda‑SARS, Rhonda‑RESPI, and Rhonda‑MRSA—detecting SARS‑CoV‑2, a panel of four respiratory viruses, and methicillin‑resistant Staphylococcus aureus, respectively. The new cartridge extends this platform to include CRP measurement and a broader viral panel.

The development followed a milestone‑based approach. In Milestone 1, the team optimized liquid handling and PCR chemistry to reduce the TAT to 25 minutes for both DNA and RNA targets. By improving primer concentrations, testing alternative polymerases, and shortening individual PCR steps, they achieved a 50–60 % reduction in liquid‑handling time and demonstrated detection of one RNA and one DNA analyte in a proof‑of‑principle run. Milestone 2 focused on developing a lysis protocol that works for both gram‑positive bacteria and viral RNA in viscous clinical samples. The same lysis reagents were then applied to a multiplex panel of four respiratory viruses—SARS‑CoV‑2, Influenza A, Influenza B, and respiratory syncytial virus (RSV). In Milestone 3, the expanded panel was validated, yielding a final TAT of 32 minutes for the four‑virus assay.

Clinical validation was carried out in two phases at UKF. Clinical Study I tested the new cartridge on patient swabs and blood samples, confirming the analytical performance observed in the laboratory. Clinical Study II further assessed the system’s robustness and user‑experience in a real‑world setting, although detailed results were not included in the report. Throughout the project, the team performed rigorous verification and validation of the fast PCR protocol, ensuring compliance with regulatory standards.

Collaboration was central to the project. Spindiag provided the microfluidic hardware, reagent formulation, and regulatory expertise; HSG contributed the CRP assay development and integration; and UKF supplied clinical samples and performed the pilot studies. The project was funded by German research agencies, with the total budget allocated across the four milestones. The partnership structure allowed each partner to focus on its core competency while sharing data and resources to accelerate development.

In summary, the project successfully produced a fully integrated POC cartridge capable of detecting SARS‑CoV‑2, three additional respiratory viruses, and CRP within 30–32 minutes. The technical achievements—significant TAT reduction, multiplex PCR optimization, and compatible bacterial lysis—demonstrate the feasibility of a single‑device solution for rapid respiratory diagnostics. The collaboration between industry, academia, and a clinical hospital ensured that the system was both scientifically robust and clinically relevant, positioning it for future regulatory approval and market deployment.