Figure 2.

Two high magnification SEM images of collagen fibril specimens. (a) The specimen appeared to be a single fibril on an uncoated fixed pad. The fixed pad showed the typical grains of polysilicon and had a cobblestone-like appearance. The collagen fibril specimen appeared to be a cylinder with a relatively smooth surface, running from left to right in the middle section. No clear D-banding pattern of the specimen was observed. This is not uncommon in SEM imaging of collagen fibrils because the appearance of D-banding pattern of collagen fibrils highly depends on the sample preparation and imaging equipment. (b) The specimen appeared to be multiple fibrils entangled together and twisted with one another on a fixed pad coated with polyimide. The fixed pad appeared to be relatively smooth because of the polyimide coating. Multiple D-banding patterns (arrowheads in b) clearly indicate the existence of multiple fibrils (approximately three fibrils in this case).