Fig 2.

a. The NGS read length distribution (insert sizes after adapter and quality trimming) from the EUA-kit N3 false positive product demonstrating three prominent populations of molecules at 36 bp, 46 bp, and 58 bp in length. All three populations were identified as originating from the N3 assay components and comprise oligonucleotide duplex or triplex molecules (Fig 2b). b. Representative NGS reads from the three most common populations of the EUA-kit N3 false-positive RT-PCR reaction products (Fig 2a). N3 primers and probes are mapped below each read (reverse primer shown in reverse-complement). The 58 bp product and 36 bp products involve the probe and therefore would have generated fluorescence in the absence of template during the reaction. These same populations of products were generated from all three sets of primers and probes (pre-EUA, EUA-kit, commercial vendor).