Table 3.

Limit of detection.

RNA concentration (copies/mL)∗	Virus concentration (TCID50/mL)	Total valid results	Test positivity (%)†		Mean Ct‡
			Target 1	Target 2	Target 1	Target 2
621	0.084	21	100	100	31.0	33.0
207	0.028	21	100	100	31.8	34.1
67	0.009	21	100	100	32.7	35.2
22	0.003	21	38.1	100	33.5	36.4
7.4	0.001	21	0	52.4	n/a	37.9
2.2	0.0003	21	0	14.3	n/a	37.2
0.7	0.0001	21	0	9.5	n/a	38.5
0 (blank)	0 (blank)	10	0	0	n/a	n/a

^∗Conversion from TCID₅₀/mL to RNA copies/mL based on information provided in the Certificate of Analysis from the vendor: one TCID₅₀/mL is equal to 7393 genome equivalents (RNA copies) by droplet digital PCR.

^†All replicates where Target 1 was positive were also positive for Target 2.

^‡Calculations only include positive results.