Fig. 2.

Lower detection limit of N gene examined primers–probe sets in wastewater matrix. RNA extracted from negative detection wastewater sample (No virus) served as wastewater matrix and spiked with known concentrations of SARS-CoV-2. Matrix was spiked with different concentration of N gene template (10⁰–10² copies per μL) or Non-Template Control (NTC, water). ND - not detected. Solid lines indicate the median and dashed lines indicate the detection limit as decided by clinical guidelines (Ct > 40).