B-195 Accelerating Molecular Diagnostics: Development of a novel Rapid, Integrated PCR System for Acute Respiratory Infections Detection

Abstract

Background The COVID-19 pandemic and acute respiratory infections have underscored the necessity for high-throughput and timely molecular diagnostics. Existing molecular diagnostic methods are labor-intensive, a challenge particularly evident in large-scale testing. This study aims to streamline the nucleic acid testing process by integrating extraction and detection in PCR testing, thereby optimizing efficiency. Methods We developed 'EXP-160R', an integrated PCR system capable of rapid thermal cycling. This innovation employs advanced temperature control technology to markedly reduce heating, cooling, and annealing-extension times. The PCR reagent-kit (Zybio Inc.) was optimized to complement the instrument's capabilities, aiming for pathogen nucleic acid detection in acute respiratory infections within 25 minutes. The precision of in-tube temperature during rapid amplification was validated by using temperature-sensitive molecular probes in system development stage. Performance evaluation used the WHO International Standard for SARS-CoV-2 RNA to assess sensitivity and detection limits. We also analyzed 500 clinical samples from multiple Chinese hospitals, including 295 COVID-19 positives and 205 negatives, comparing the EXP-160R system's performance with an NMPA-approved PCR kit. Results The innovative system significantly improved PCR cycle times, enabling detection of 16 samples in 22 minutes and a throughput of 2400 tests per day, without compromising sensitivity or specificity. Validation confirmed a detection limit of 200 copies/mL, and the system achieved a 100% detection rate for medium and high viral load samples, with a coefficient of variation (CV) for Ct values ≤ 5%. Clinical trial comparisons with clinical standard diagnostics revealed a sensitivity of 98.05%, specificity of 100%, accuracy of 99.2%, and a Kappa coefficient of 0.984. When compared to the established PCR kit, our system showed comparable efficacy, with a sensitivity of 98.50%, specificity of 98.67%, accuracy of 98.6%, and a Kappa of 0.971. Conclusions The rapid PCR system represents a significant advancement in molecular diagnostics, offering rapid, high-throughput, and accurate detection of SARS-CoV-2. This system is particularly beneficial in urgent testing scenarios, such as airports and fever clinics. It addresses current pandemic needs and sets a new benchmark for future respiratory and infectious disease diagnostics, enhancing both efficiency and user experience.