Fig. 1.

RT-qPCR detection of SARS-CoV2, PMMoV, and BCoV in wastewater sample concentrated by different methods. Method 1 or 1.A performed significantly better than method 2 and 2.A for all samples. Fold change values were generated for RT-qPCR wastewater samples concentrated by four different methods from Stockholm and North of Italy using the 2^−ΔCt method, and normalized to input (RNA extracted from corresponding 8 ml wastewater) with Stockholm 1 sample and Method 1.A set at value 1. A. SARS-CoV-2 N gene B. nPMMoV C. Recovery rate of spiked BCoV. Error bars: SD. Student's t-test were used to calculate statistical significance, and is indicated for comparison between Method 1 and 2, and 1A and 2A. (*p < 0.05, **p > 0.01, ***p < 0.001).