Wastewater SARS-CoV-2 sequencing
Two PCR reactions were performed for every sample, each one with one Pool of ARTIC primers. PCR reactions consisted in 12 L of DreamTaq Master Mix, 4 L of the respective ARTIC Primer Pool (10 M), 2.5 L cDNA and 6.5 L of Nuclease free water for a total reaction volume of 25 L. Cycling conditions were 1x (98C, 30s), 30x (98C, 15s; 65C, 5min). After this, PCR products were merged for each sample and submitted to purification. Samples quality and concentration were measured and sequencing libraries were prepared using the Nextera XT DNA Library Preparation Kit (Illumina). Finally, amplicon sequencing libraries were sequenced in an Illumina NovaSeq6000 equipment (Macrogen, Korea).