title: 18SV9-Seq of microbiome: Lake Towuti: Quaternary sediments
design: Using stringent precautions to prevent contamination, environmental DNA was extracted with the DNeasy PowerMax Soil Kit (Qiagen) from 2 to 8 g of Quaternary Lake Towuti sediments (4.12-116.57 mcd). We followed the protocol for 16S rRNA gene library preparation for MiSeq sequencing as outlined by Caporaso et al. (2012), where the template-specific 16S V3V4 primer sequences were replaced with forward and reverse template-specific primer sequences targeting eukaryotic 18SV9 (Amaral-Zettler et al. 2009). A total of 82 sediment intervals yielded 18SV9 amplicons. Equimolar amounts of each amplicon, which included the Illumina adapters and unique 12 bp Golay barcodes added to the reverse primers, were pooled and gel-purified. The resulting library was sequenced at the Australian Genome Research Facility (AGRF) in Perth (paired-end; 300 cycles) using the sequencing facility's default procedures. Background PCR Blanks (BGB) and Extraction Blanks (EB) were sequenced alongside the samples.