<p>Nano-SiO<sub>2</sub> particles were incubated with 1.25% serum only or 1.25% serum and A549 cells. The nanoparticles were recovered and washed by centrifugation and then bound proteins separated by SDS-PAGE which were stained with InstantBlue. For proteomic analysis the gel was cut into 11 horizontal slices based on the migration of proteins markers and the bands in the material eluted from the nanoparticles. Each slice was further divided between each of the protein lanes for analysis by proteomics as detailed in the Materials and Methods.</p
