title: Metabarcoding of PCR blank
design: The V1-V2 region of the nuclear 18S rRNA gene (18S V1-V2) using primers F04: 5' GCTTGTCTCAAAGATTAAGCC 3' and R22mod: 5' CCTGCTGCCTTCCTTRGA 3' (∼365 bp; (Fonseca et al. 2010; Sinniger et al. 2016) was amplified using polymerase chain reaction (PCR). PCR amplification was conducted in duplicate and products were pooled for library preparation. Pooled amplicons were purified using AMPure® XP beads (Beckman Coulter®), quantified using a Qubit® 1X dsDNA High Sensitivity Fluorescence kit (Thermofisher Scientific). Full methods description is reported at publication in Supplementary file S1.