Electron Cryomicroscopy of Fibrillar Collagens - Methods in Molecular Biology: Extracellular Matrix Protocols - page 93

Fig. 2. (A) Electron image of reconstituted collagen fibril after freeze-etching using
the mica ice wedge method and rotary shadowing with Pt/C at 11 . (B) Average axial

projection from images similar to (A) , shown repeated over two D -periods. The inten-
sity relates to the local thickness of platinum, revealing ridges on the fibril surface.
There are three conspicuous ridges: two corresponding to the telopeptide domains and
an additional ridge in the gap region. The underlying gap/overlap structure of the fibril
is still apparent.

°

3. Acid-soluble type I collagen from bovine skin (8) .

4. Fine forceps (Agar Scientific).

5. Ultrapure water (Purite Stillplus HP).

6. 50-Grade filter paper (Whatman).

7. Aluminium spacer 15 mm × 15 mm × 0.25 mm.