Resource-efficient internally controlled in-house real-time PCR detection of SARS-CoV-2

Table 5 Interpretation of results obtained with the RKI/ZBS1 SARS-CoV-2 protocol

	SARS-CoV-2		Inhibition control	Nucleic acid control	Result	Comments
#	E-Gene	orf1ab	KoMa	c-myc
1	< 38	< 38	Any	Any	Positive
2	< 38*	≤ 45*	32 ± 3	Signal	Positive
3	≤ 45*	< 38*	32 ± 3	Signal	Positive
4	≥ 38	≥ 38	32 ± 3	Any	Ambiguous	if curves are distinctly positive; if not, analyze follow-up sample
5	Signal	Negative	32 ± 3	Signal		repeat PCR with 10 µl
6	Negative	Signal	32 ± 3	Signal		repeat PCR with 10 µl
7	Negative	Negative	32 ± 3	Negative	Invalid	analyze follow-up sample
8	Negative	Negative	> 35	Any	Invalid	repeat extraction with 1:10 dilution
9	Negative	Negative	32 ± 3	Signal	Negative

Besides clearly positive and clearly negative results showing the controls as expected, unequivocal results can be obtained in particular with low concentrations of viral RNA. Measures for confirmation of such results are described in the table
^*If ΔCT value is > 3 repeat PCR with 10 µl of RNA template

ISSN: 1743-422X