Figure 2: Microscopical observation comparing between the cytotoxic effect produced by nanoparticles on Raw 264.7 cells at high concentration (40 μg/ml), A. illustrating no cytotoxic effect produced after 3 hours incubation with 40 μg/ml of AuNSs , B. AgNSs at the same concentration and the same exposure time result in severe cell death. (10X objective).