Clin Infect Dis. 2021 Apr 8:ciab063. doi: 10.1093/cid/ciab063. Online ahead of print.
An ultra-sensitive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid antigen assay (S-PLEX, MesoScale Diagnostics) was evaluated in 250 retrospective and 200 prospective upper respiratory specimens. In samples with cycle threshold <35, there was 95%-98% positive and 93%-96% negative percent agreement with reverse transcription-polymerase chain reaction. S-PLEX may provide a high-throughput alternative to nucleic acid-based testing for coronavirus disease 2019 (COVID-19) diagnosis.