16S amplicon sequencing of non-template negative control
Nuclease free water was used as a non-template control. The V3-V4 region was PCR amplified with 341F (CCTAYGGGRBGCASCAG) and 806R (GGACTACNNGGGTATCTAAT). Illumina indices were added using a further PCR reaction with primers containing appropriately indexed Illumina adapters with overlaps to the V3-V4 primers.