Comparison of Four Molecular In Vitro Diagnostic Assays for the Detection of SARS-CoV-2 in Nasopharyngeal Specimens

Wei Zhen; Ryhana Manji; Elizabeth Smith; Gregory J Berry

The LoD established by percent positive rate ranged from 1,000 copies/mL by both the GenMark and the 172 modified CDC assays to 50 copies/mL by the DiaSorin Molecular assay ( Table 2) . The LoD results were 173 further subjected to Probit analysis. The 95% detection limit of the CDC assay was 779 ± 27 copies/mL for 174 the N1 gene and 356 ± 20 copies/mL for the N2 gene. For the DiaSorin Molecular assay, the 95% detection 175 limit was 39 ± 23 copies/mL for the S gene and 602 ± 28 copies/mL for ORF1ab. For the Hologic assay, the 176 95% detection limit was 83 ± 36 copies/mL for ORF1ab. Probit analysis could not be performed for the 177 GenMark assay ( Table 2) . The final LoD, according to the assay results interpretation algorithm from each 178 manufacturer, ranged from 1,000 copies/mL by the GenMark assay to 39 ± 23 copies/mL by the DiaSorin 179 Molecular assay ( Table 2) . 180 All rights reserved. No reuse allowed without permission.