design:  The PCR amplification of archaeal 16s rRNA genes was conducted using         specific primer Ar915aF (AGGAATTGGCGGGGGAGCAC) and Ar1386R (GCGGTGTGTGCAAGGAGC). Each primer         contained Illumina adapter and unique barcode. Each cDNA sample was amplified in duplicates,         and 3 wells per run served as a negative control for the master mix. After amplification,         the duplicate PCR products were pooled, and the correct sizes of PCR products and the         absence of signal from negative controls were further verified through agarose gel         electrophoresis. Quantitation of amplicons was performed in a Synergy HTX Multi-Mode         Microplate Reader using a Quant-iT dsDNA Assay Kit. The amplicons were pooled in equimolar         concentrations and purified using an Agencourt AMPure XP and then further quantified as         described above. The amplicon library was combined with Phix Control library and sequenced         in the Illumina Miseq.
library_construction_protocol: Miseq 16s rRNA