title: Virome of gills from fish: Fishsai098
design: For viral metagenomic analysis, a total of 32 fish were caught and dissected from September 2020 to November 2020 in the Lhasa River basin, Tibet, and a total of 292 samples of intestinal contents, gills, and tissues, including muscle, liver, swim bladder, heart, and brain, were taken from each fish. They were randomly pooled into 18 specimen pools of 6 specimens each based on three groups of intestinal contents, gills, and tissues.  The pools were individually homogenized with a mortar and pestle, resuspended in 1 mL DPBS, and then frozen and thawed rapidly three times on dry ice. The supernatants were then collected after centrifugation (10 min, 15,000 g). Supernatants were filtered through a 0.45-mm filter (Millipore) to remove eukaryotic- and bacterial cell-sized particles, and 500 L of supernatant from each pool was then subjected to a mixture of nuclease enzymes to reduce the concentration of free (non-viral encapsidated) nucleic acids. The remaining total nucleic acid is then isolated using the QIAamp MinElute Virus Spin Kit according to the manufacturer's protocol. Eighteen libraries were then constructed using the Nextera XT DNA Sample Preparation Kit (Illumina) and sequenced on the Illumina NovaSeq 6000 platform, each with 250 base-paired double barcodes.