16S rRNA gene amplicons from DNA extraction negative controls.
DNA extracted from a clean swab (DNA extraction negative control) was used to construct the 16S rRNA gene library (V4 16S rRNA gene) following the protocol from the Schloss lab and Centeno-Martinez et al. 2022. The 16S rRNA gene amplicons were sequenced using Ilumina MiSeq (2x250, paired-end)..