50 ml syringe

BV stock or 10 ng/μL DNA standard (control) was diluted two-fold in 20% trehalose/2x TE buffer for a final solution of 10% trehalose/TE. 6 mL of diluted viral stock was added to a BD 50 mL syringe. Diluted viral stock was pumped at 1 mL/min through a SonoTEK 8700–120 MS, 120 kHz nozzle (Milton, NY) set at 2 W to produce droplets approximately 18 μm in diameter.^{30 (link)} Control samples were pumped through the nozzle without sonication enabled. Droplets were immediately collected in a 50-mL conical tube; the distance between the nozzle and the conical tube wall was adjusted so that the time between droplet formation and droplet coalescence as the droplets impinged on the tube walls was approximately 100 ms. Samples were kept on ice until use or assay. For this experiment, residual DNA was measured for diluted BV stock pumped through the nozzle at 0 W (no atomization), and samples of thermally-disrupted BV (suspensions of BV incubated in TE/2% PS80 for 3 hr. at 60C) were atomized to control for adsorptive losses of DNA on interior surfaces of the sonication system.

The respiratory tract including intact lungs and trachea was removed from animals immediately following euthanasia. Forty milliliters of cold PBS was then added through the trachea using a 50 ml syringe (BD, Heidelberg, Germany). The lung tissue was gently massaged by hand and inverted to collect the fluid in 50 ml conical tubes. The BALF was then centrifuged for 10 minutes at 800g at 4°C. The supernatant was collected and stored at -80°C.

Sediment cores, four-centimeters in depth, were collected from around the edge of 12 fully thawed meltwater ponds during the summer season in January 2013 from Bratina Island (6 ponds) (78° 01′ S, 165° 32′ E) and the Miers Valley (6 ponds) (78° 07′ S, 164° 12′ E) (Table 1, Figure 1). Sites were selected to encompass a broad range of surface water geochemistry from ponds at each location. Cores were aseptically collected using a disposable push-corer developed from a 50 mL syringe (BD, Singapore). The corer (with the plunger removed) was inserted 4–6 cm into the sediment, the plunger reinserted and core removed carefully to retain the sediment structure. After excess sediment was removed, each core was sub-sectioned into four one-centimeter samples, placed in sterile 15 oz whirlpack (Nasco, WI, USA), then frozen for transportation to the laboratory.