A Highly Sensitive Point-of-Care Covid-19 Serological Test using Immuno-PCR in 35 Mins

Serological tests play important roles in the fight against the Coronavirus Disease 2019 (COVID-19). The most commonly used methods, enzyme-linked immunosorbent assays (ELISA), provide reliable and sensitive antibody measurement though they require bulky laboratory infrastructure as well as lengthy turnaround time. Conversely, lateral flow immunoassays (LFIA) are suitable for rapid point-of-care tests but with limited sensitivity. To combine the best attributes of ELISA and LFIA, we developed a novel streamlined immuno-PCR assay and applied it to a portable magnetofluidic instrument for point-of-care serological tests. In testing 107 clinical samples, our point-of-care serological test showed 98.3% (58/59) specificity and 93.8% (45/48) agreement with benchtop immunoassays. Moreover, 100% agreement was achieved by only slightly increasing the total assay time to 45 min, demonstrating its potential as a new point-of-care serological test for COVID-19 and beyond.