Point-of-Care CRISPR-Cas-Assisted SARS-CoV-2 Detection in an Automated and Portable Droplet Magnetofluidic Device

Chen, Fan-En; Lee, Pei-Wei; Trick, Alexander Y.; Park, Joon Soo; Chen, Liben; Shah, Kushagra; Mostafa, Heba; Carroll, Karen C.; Hsieh, Kuangwen; Wang, Tza-Huei

In the fight against COVID-19, there remains an unmet need for point-of-care (POC) diagnostic testing tools that can rapidly and sensitively detect the causative SARS-CoV-2 virus to control disease transmission and improve patient management. Emerging CRISPR-Cas-assisted SARS-CoV-2 detection assays are viewed as transformative solutions for POC diagnostic testing, but lack of streamlined sample preparation and full integration within an automated and portable device hamper their potential for POC use. We report herein POC-CRISPR – a single-step CRISPR-Cas-assisted assay that leverages facile magnetic concentration and transport of nucleic acid-binding magnetic beads to incorporate sample preparation with minimal manual operation. Moreover, POC-CRISPR has been adapted into a compact thermoplastic cartridge within a palm-sized yet fully-integrated and automated device. During analytical evaluation, POC-CRISPR was able detect 1 genome equivalent/μL SARS-CoV-2 RNA from a sample volume of 100 μL in < 30 min. Finally, when evaluated with 27 unprocessed clinical nasopharyngeal swab eluates that were pre-typed by standard RT-qPCR (C(q) values ranged from 18.3 to 30.2 for the positive samples), POC-CRISPR achieved 27 out of 27 concordance and could detect positive samples with high SARS-CoV-2 loads (C(q) < 25) in 20 min.