Dataset: ETNP Viromes
Deployment: NH1315

Detailed protocols, including suggestions from the scientific community, are published on the lab website at https://u.osu.edu/viruslab/protocols/ and maintained on protocols.io at https://www.protocols.io/workspaces/sullivan-lab.

Samples were collected from the Eastern Tropical North Pacific oxygen minimum zone region (ETNP OMZ) during the OMZ Microbial Biogeochemistry Expedition cruise (R/V NewHorizon,13-28 June 2013). Seawater was collected from 16 depths spanning the mixed layer, oxycline, OMZ core, and below the OMZ. Collections were made using Niskin bottles on a rosette. Samples were preserved with EM-grade glutaraldehyde (2% final concentration), flash-frozen in liquid nitrogen and stored between -72 °C and -80 °C until analysis.

After resuspension in ascorbic-EDTA buffer (0.1 M EDTA, 0.2 M Mg, 0.2 M ascorbic acid, pH 6.0), viral particles were concentrated using Amicon Ultra 100-kD cen- trifugal devices (Millipore), treated with DNase I (100 U/mL) followed by the addition of 0.1 M EDTA and 0.1 M EGTA to halt enzyme activity, and extracted. Viral particle suspensions were treated with Wizard Polymerase Chain Reaction Preps DNA Purification Resin (Promega, Fitchburg, WI, USA) at a ratio of 0.5 ml sample to 1 ml resin, and eluted with TE buffer (10 mM Tris, pH 7.5, 1 mM EDTA) using Wizard Minicolumns. Extracted DNA was Covaris-sheared and size-selected to 160 to 180 bp, followed by amplification and ligation per the standard Illumina protocol. Sequencing was done on a HiSEq 2000 system at the DOE Joint Genome Institute.