Résumé
The need to develop high-throughput diagnostic platforms for infectious diseases has never been more evident than with the emergence of SARS-CoV-2 and the ensued COVID-19 pandemic. Microfluidics, in tandem with its multiplexing capabilities, high sensitivity, and potential for automation, provides a unique advantage towards the development of high-throughput serological diagnostic platforms. Here, we present a microfluidic device that detects IgG or IgM raised against four SARS-CoV-2 antigens (spike, S;S1 subunit, S1;the receptor-binding domain, RBD;and nucleocapsid, N) from 50 serum samples in parallel. We validated the platform with a cross-sectional cohort of 66 samples from confirmed COVID-19 patients and a pre-pandemic control of 34 serum samples collected in 2018. The analysis of both antibodies against all four viral antigens provided a sensitivity of 90.4% and a specificity of 94.1%, with both parameters increasing to 100% in late-stage samples (21-30 days after symptoms onset). We expect our device to open the door to massive serological testing, impacting diagnostics, vaccine development, and epidemiological understanding of COVID-19. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.
Résumé
Massive PCR testing during the COVID-19 pandemic was difficult due to the insufficiency of instruments and reagents. We developed a portable thermocycler for RT-qPCR that combines thermal control and fluorescence detection into a highly integrated hybrid module. Our thermocycler, named HybOT Cycler, is Bluetooth-controlled from an Android tablet. We also developed a bubble-free microfluidic device to run the PCR assays. The acrylic mold for the replication of the microfluidic device and the instrument were fabricated with 3D printed parts or micromilling. Concentrations as low as 1000 copies/µL of the SARS-CoV-2 N1 gene were detected, similar to a benchtop thermocycler. Finally, we analyzed 20 samples tested positive for SAR-CoV-2 and 10 controls, obtaining a sensibility of 95% and specificity of 100%. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.