Fig. 1.
PM2.5 does not affect macrophage viability and pneumococcus survival. a Transmission electron micrograph of the particulate matter. The magnified images of cropped areas are shown in the right panels. Original magnification: 3000× (upper panel) and 8000× (lower panel). Scale bars, 1 μm. b Cell viability of RAW264.7 cells exposed to low (5 μg/ml) or high (20 μg/ml) doses of PM2.5 for 24 h, analyzed with MTT assay. c Pneumococcus incubated with low or high PM2.5 doses for 6 h. Bacteria grown on the blood agar plates were counted and expressed as colony-forming units (CFU). Results are presented as mean ± standard deviation from triplicate independent experiments