Table A2.

SARS CoV-2 detection – positive controls. Air samples from sampling period 02.-09.04.2020 (sample 122), 09.-16.04.2020 (sample 123) and 16.-23.04-2020 (sample 124) were spiked with a) 1 × 10⁷ and b) 1 × 10⁴ SARS-CoV-2 genome equivalents (Geq) to exclude a potential interference of sample matrix to Geq detection. * SARS-CoV-2 PCR; E, RdRp and N gene, measured without prior cell cultivation, day 0; ** SARS-CoV-2 PCR; E, RdRp and N-Gen, measured after cultivation for 8 days.

Sample #	Characteristics	Spiked with SARS-CoV-2 (Geq)	SARS-CoV-2 PCR (Geq) day 0a	Virus-induced CPE	SARS-CoV-2 PCR (Geq) day 8b
122a	Week 02.-09.04. (Air sample)	1 × 107	0.91 × 107	+++	>1 × 108
122b	Week 02.-09.04. (Air sample)	1 × 104	1.24 × 104	++	2.1 × 107
123a	Week 09.-16.04. (Air sample)	1 × 107	0.96 × 107	+++	>1 × 108
123b	Week 09.-16.04. (Air sample)	1 × 104	0.98 × 104	++	9.7 × 107
124a	Week 16.-23.04. (Air sample)	1 × 107	0.97 × 107	+++	>1 × 108
124b	Week 16.-23.04. (Air sample)	1 × 104	0.98 × 104	++	5.7 × 107

Note: there was no inhibition of SARS-CoV-2 replication.

^aSARS-CoV-2 PCR; E, RdRp and N gene, measured without prior cell cultivation, day 0.

^bSARS-CoV-2 PCR; E, RdRp and N-Gen, measured after cultivation for 8 days.