title: Bacteria on conditioned PVDF membranes
design: Amplification of the 16S V6-V8 region (16S rDNA) was performed using a two-step dual-indexed PCR approach specifically designed for Illumina instruments. In a first step, the gene specific sequence is fused to the Illumina TruSeq sequencing primers and PCR was carried out. The second PCR step, performed with 50- to 100-fold dilution of the previously purified PCR product as a DNA template, allowed the addition of barcodes (dual-indexed) and the missing sequence required for Illumina sequencing. Barcoded amplicons were then pooled in equimolar concentration for sequencing on the Illumina Miseq.