Figure 7: Live-dead cell staining assay: microscopic analysis and quantitative evaluation. (a) High number of green-labeled living bacteria after 16 h incubation in LB, without Ag/PS. (c), (d): high number of red-labeled dead bacteria after 16 h incubation +30 wt.% Ag/PS film (1 cm × 1 cm − 0.0177 mg) obtained by using a mild thermal annealing treatment (c); similar results were observed in bacteria culture after 16 h of incubation with Ag powder (d). Scale bar represents 20 μm. (b) Quantitative analysis of the E. coli viability (%) after 16 h incubation at each condition reported in Table 1 (A–E).