Sequencing of the fungal ITS amplicon of PCR grade water (negative control)
PCR grade water was used to construct the fungal ITS (Internal Transcribed Spacer) library  following the protocol from the Earth Microbiome Project. The amplified DNA was normalized using the SequalPrep Normalization Plate (Invitrogen) and pooled to form a single library. The ITS amplicons were sequenced using Ilumina MiSeq (2x250, paired-end).