Digital droplet PCR (ddPCR) reliably quantifies SARS-CoV-2 RNA standards. (a) Fluorescence microscopy images of ddPCR using CDC N1 primer set with 1000 input copies of SARS-CoV-2 RNA and (a′) no template control. (b) Fluorescence intensities as measured by BioRad QX200 Droplet Reader for 10,000 input target copies and (b′) no template control. (c) Quantitative reverse transcription PCR (qRT-PCR) standard curve using CDC N1 primer set and SARS-CoV-2 RNA shows expected linear relationship between input viral copy number and cycle threshold (Ct) value with an estimated limit of detection (LoD) of 10 copies per reaction. (d) ddPCR standard curve for SARS-CoV-2 RNA reveals accurate viral copy number measurement with an estimated LoD of 10 copies per reaction.