"II003F (Danube km 2354) -- run number 4, pool number 1, barcode number 4."
"Water was sampled and cells were captured on 0.2 µm filters and 3.0 µm for the free-living and attached fraction respectively. Samples were kept frozen under -80°C. Nucleic acids were extracted using a slightly modified protocol of a previously published phenol-chloroform, bead-beating procedure (Griffiths et al., 2000) using isopropanol instead of polyethylene glycol for DNA precipitation. Primers targeting the V3 and V4 regions of the ribosomal RNA gene originally designed for pyrosequencing (Herlemann et al. 2011.) were adapted to Illumina sequencing. The DNA material was amplified using  duplicated 20-cycles PCR according to Sinclair and al. 2015. In a second step PCR barcodes were added. All PCRs were conducted in 20 µl volume using 1.0 U Phusion high fidelity DNA polymerase (NEB, UK), 0.25 µM primers, 200 µM dNTP mix, and 0.4 µg bovine serum albumin. Following this, the solution was purified by magnetic bead purification and quantified using a fluorescent stain-based kit (PicoGreen, Invitrogen)"