Figure 2. Stain uptake by PCSA sections.

H&E stain uptake by 5 µm thick sections of (a) clear and (b) pigmented aerogel samples. The out-of-focus regions of the image (indicated by arrows) reflect the three dimensional nature of the aerogel material. While the pores cannot be visualized by a light microscope, the darker regions are interpreted as openings to the three dimensional porous structure. Images were taken with an upright Nikon Eclipse 800 microscope. Striations noticed in (a) are attributed to sectioning artifacts.