Collagen fibrils, electron micrograph

Figure 29-10 Schematic diagram of collagen molecules in a fibril so arranged as to give the 640-A spacing visible in electron micrographs...

An electron micrograph of collagen fibrils from skin. (Courtesy of Jerome Gross, Massachusetts Genera] Hospital.)... 

Ronziere, M-C., Herbage, B., Herbage, D., and Bemengo, J-C. (1998). Fourier analysis of electron micrographs of positively stained collagen fibrils Application to type I and II collagen typing. Int. J. Biol. Macromol. 23, 207-213. 

Fig. 1. (A) Scanning electron micrograph of human skin. The epidermis has pulled away from part of the basement membrane. (B and C) Transmission electron micrograph through the epidermal-dermal junction of human skin. Keratinocytes (KF) are the cells in the human epidermis. LD, The lamina densa of the basement membrane LL, the lamina lucida. Typical anchoring fibrils (AF) formed from type VII collagen are shown at higher power in C. Courtesy of Dr. K. Holbrook, University of Washington.

Figure 3.29. Relationship between proteoglycans and collagen fibrils in tendon. Transmission electron micrograph showing positive staining pattern of type I collagen fibrils from rabbit Achilles tendon stained with quinolinic blue. Proteoglycan filaments (arrows) are shown attached to collagen fibrils.

Figure 5.12. Lateral fusion of collagen fibrils during fascicle development of chick extensor tendon. Transmission electron micrograph showing the lateral fusion of collagen fibrils at day 17 of chick embryogenesis. Note that the demarcation between collagen fibrils (arrows) is less clear compared to the cross section shown at day 14 (Figure 5.11). Several fibrils appear to be in the process of fusion generating fibrils with irregular cross sections. The fibril bundle (fiber) diameter is still about 2 pm before fusion similar to that observed on day 14 (see Silver et al., 2003).

Fig. 12. Electron micrograph of air-dried, chromium-shadowed collagen fibrils from adult human corium magnification X 26,000, (From Gross and Schmitt, 1948.)...

Reed and Rudall (182) studied the cuticle of the earthworm Allolobo-phora longa), securing by an ingenious stripping technique electron micrographs of layers of the crossed collagen-type fibrils secreted by columnar epithelial cells. Most important for the present discussion they reported inability to observe in their material the banded appearance characteristic of the usual connective tissue fibrils. 

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