Quantitative Reverse Transcription- Polymerase Chain Reaction
SARS-CoV-2 copies of NP1 in nasal swab viral transport medium (VTM) were quantified by qRT-PCR using the CDC-recommended kit (CDC-006-00019, Revision: 03). Viral RNA was extracted according to manufacturer’s instructions (QiaAmp Viral RNA kit). Regression analysis of threshold cycle number versus a serial dilution of a NP1 gene standard (Integrated DNA Technologies) was used to determine NP1 copy number. Data were normalized to input RNA and reported as copy/mL of VTM.