Estimated frequency of lytic viral infection from samples collected in the Eastern Tropical North Pacific oxygen minimum zone region (ETNP OMZ) on R/V New Horizon cruise NH1315 during June 2013 (NCEI Accession 0278154)

Acquisition Description:
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. The FVIC protocol can be found at dx.doi.org/10.17504/protocols.io.dbp2mm .

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.

Samples were centrifuged for 1 h at 55 000 g using an ultracentrifuge (LM-80, Beckman, Brea, CA, USA) onto TEM grids (200 mesh copper grids with carbon- stabilized formvar support; Ted Pella, Redding, CA, USA). Grids were then stained with uranyl acetate and analyzed as previously described (Brum et al., 2005) to determine the frequency of visibly infected cells using a transmission electron microscope (CM12, Philips, Eindhoven, The Netherlands). The frequency of infected cells was then calculated from the frequency of visibly infected cells (Binder, 1999).