Development of a fully automated high throughput PCR for the detection of SARS-CoV-2: The need for speed

Figures & data

Table 1. Ct-Values of the LightCycler480 system and the NeuMoDx N96 for the detection of in-vitro transcribed RNA containing the amplicon region of SARS-COV2 (three measurements for each sample), cell culture heat inactivated SARS-COV2 (two measurements for each sample) and respiratory specimen of a patient with confirmed COVID-19 (one measurement for each sample), according to a dilution row series. Every given Ct-value indicates one PCR run. Bottom section shows the assessment of the specificity. ^#The 89 bp long artificial RNA fragment was too short for the extraction with the “MagNa Pure compact system”; ^§The precision of Ct-values are attenuated at extremely low virus concentrations. *refers to the Ct-value of the LightCycler 480II.

RNA concentration	Ct-Values Lightcycler 480II	Ct-Values NeuMoDxN96
In-vitro transcribed RNA
10e^5 (cp/ml)	not performed	23.3/24.2/24.2
10e^4 (cp/ml)	not performed	27.4/27.4/27.4
10e^3 (cp/ml)	not performed	30.6/31.6/30.7
10e^2 (cp/ml)	not performed	34.5/33.5/33.9
10e^1 (cp/ml)	not performed	neg/41.6/neg
Inactivated cell culture SARS-COV2
1.6e^2 (cp/µl)	29.78/29.7	24.1/25.8
1.6e^1 (cp/µl)	32.5/32.5	29.9/28.9
1.6e°^.1 (cp/µl)	34.47/34.9	32.1/32.6
1.6e°^.01 (cp/µl)	Neg/neg	37.3/34.6
Clinical sample (respiratory specimen, undiluted Ct 23.4*)
1:10	25.5	22.8
1:100	28.8	24.6
1:1,000	32.7	29.3
1:10,000	36.8	34.8
1:100,000	neg	34.6
Assessment of Specificity
Influenza A	neg	neg
Influenza B	neg	neg
RSV	neg	neg