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

In the fight against COVID-19, there remains unmet needs in developing 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. Although recent CRISPR-Cas-assisted SARS-CoV-2 detection assays (such as DETECTR and SHERLOCK) are viewed as transformative solutions for POC diagnostic testing, their lack of simple sample processing and full integration within an automated and portable device hamper their potential for POC use. We report herein POC-CRISPR - a new single-step CRISPR-Cas-assisted assay that is coupled to droplet magnetofluidics (DM) - that leverages simple magnetic concentration and transport of nucleic acid-binding magnetic beads to accomplish sample preparation and assay automation. By further adapting the assay into a fully integrated thermoplastic cartridge within a palm-sized mobile device, POC-CRISPR was able to detect 1 genome equivalent (GE)/L SARS-CoV-2 RNA from a sample volume of 100 L in 30 min. Moreover, when evaluated with unprocessed clinical nasopharyngeal (NP) swab eluates, POC-CRISPR identified SARS-CoV-2 positive samples in as short as 20 min and achieved full concordance with standard RT-qPCR.