PMC:3463543 / 7735-10643 JSONTXT

{"project":"2_test","denotations":[{"id":"23056454-13713229-92972547","span":{"begin":833,"end":834},"obj":"13713229"},{"id":"23056454-5404072-92972548","span":{"begin":838,"end":840},"obj":"5404072"},{"id":"23056454-13904777-92972549","span":{"begin":991,"end":993},"obj":"13904777"},{"id":"23056454-5404072-92972550","span":{"begin":997,"end":999},"obj":"5404072"},{"id":"23056454-14774528-92972551","span":{"begin":1173,"end":1175},"obj":"14774528"},{"id":"23056454-5404072-92972552","span":{"begin":1179,"end":1181},"obj":"5404072"},{"id":"23056454-987765-92972553","span":{"begin":1311,"end":1313},"obj":"987765"},{"id":"23056454-5404072-92972554","span":{"begin":1317,"end":1319},"obj":"5404072"}],"text":"Exposure of IAV in Droplets to Various RH\nWe exposed IAV in droplets to specific RHs in the range of 17% to ∼100% at room temperature (20–24°C). The droplets consisted of four different types of media (Table 1), chosen to isolate the effects of salts and/or proteins on viability, or mucus. PBS and DMEM were used as surrogates of media that contain inorganic salts at physiological levels but no or negligible amounts of proteins. The third and fourth types of media were PBS and DMEM supplemented with 5% FCS, a source of proteins.\nTable 1 Media used in studies of influenza A virus viability versus RH.\nStudy Media Salt content Protein content Other components Reference\nHemmes et al. 1960 1 part allantoic fluid and one part2% Difco peptone ∼2.3 g L−1 (0.4 g L−1 K+, 0.9 g L−1 Na+,0.9 g L−1 Cl−)a 10 g L−1 peptone -b [8], [43]\nHarper 1961 Allantoic fluid diluted 1∶8 or 1∶10 incasein McIlvaine’s buffer (pH 7.2) ∼2.2 g L−1 (mainly Na2HPO4) a ∼1.9 g L−1 mainly casein -b [13], [43], [44]\nShechmeister 1950 Allantoic fluid in 0.1 M Sorensen’sphosphate buffer (pH 7.1) 19.6 g L−1 (8.09 g L−1 NaH2PO4, 9.51 gL−1 Na2HPO4) ∼1 g L−1 in allantoicfluid -b [15], [43]\nSchaffer et al. 1976 MEM 9.88 g L−1 (6.8 g L−1 NaCl, 2.2 g L−1NaHCO3, and others) 0 Amino acids, vitamins,glucose, others [14], [43], [45]\nMEM+0.1% BSA 9.88 g L−1 1 g L−1 Same as above\nAllantoic fluid ∼4.7 g L−1 (0.8 g L−1 K+, 1.8 g L−1 Na+,1.8 g L−1 Cl−)a ∼1 g L−1\nThis work PBS (pH 7.2) 9.55 g L−1 (8 g L−1 NaCl, 0.2 g L−1 KCl,1.15 g L−1 Na2HPO4, 0.2 g L−1 KH2PO4) 0 None\nPBS+5% fetal calf serum (FCS) Same as above ∼3.5 g L−1 Other componentsfrom FCS\nDulbecco's modified Eaglemedium (DMEM) 10.92 g L−1 (6.4 g L−1 NaCl, 3.7 g L−1NaHCO3) 0.42 g L−1 Amino acids, vitamins,glucose, others\nDMEM+5%FCS Same as above ∼3.9 g L−1 Same as above\na Estimated;\nb Detailed composition of allantoic fluid is unknown. Ten µL of stock PR/8 IAV was added into 90 µL of either PBS, PBS+5% FCS, DMEM, DMEM+5% FCS, or mucus to produce spiking solutions. The spiking solutions were distributed onto a 12-well cell culture plate, 1 µL per droplet, 10 droplets per well, and 3 replicates (i.e., 3 wells) for each medium. The plate was immediately placed into the desiccator and was incubated at a specific RH at room temperature for 3 h for model media and 2 h for mucus. At the end of the period, the virus in each well was collected with 1 mL of DMEM supplemented with 1 µg mL−1 TPCK trypsin (collection medium), by pipetting the medium ∼10 times to rinse the virus from the well. The spiking solutions were stored on ice during the incubation period, and 10 µL of each spiking solution was supplemented with 990 µL of collection medium for use as a control. Samples and the corresponding controls were titrated at the same time by TCID50 assay either immediately after collection or were stored at −80°C until testing."}