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The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.04.17.20069864 doi: medRxiv preprint performed both the modified CDC and GenMark assays when it came to overall LoD, with GenMark having 253 the overall highest LoD of all four platforms evaluated. DiaSorin Molecular had the lowest LoD (39 ± 23 254 copies/mL), closely followed by Hologic (83 ± 36 copies/mL). The modified CDC assay showed a final LoD, 255 of 779 ± 27 copies/mL based on the results interpretation algorithm. It is worth mentioning that this assay 256 requires both targets to be fully detected, thus clinical samples falling in this concentration range would 257 be identified and repeated, potentially generating additional turnaround time and laboratory labor. In 258 contrast, GenMark could only detect 100% of replicates at 1,000 copies/mL, and was not able to reliably 259 detect replicates below 1,000 copies/mL, thus patient specimens below this concentration range could 260 potentially be missed. One important limitation to mention is that sensitivity using Probit analysis could author/funder, who has granted medRxiv a license to display the preprint in perpetuity.