Comparisons of Techniques - Sample Preparation Topic for Transmission Electron Microscopy - page 231

3.5.2 Comparison of “Negative-Staining” and “Decoration-Shadowing”
Contrast, and “Freeze-Fracture” Techniques

Negative-Staining Technique (“Techniques” Chapter 7, Section 2) , Decoration
Shadowing (“Techniques” Chapter 7, Section 1) , and Freeze Fracture (“Techni-
ques” Chapter 5, Section 4)

Fine particle material: collagen fibers in a tissue or isolated fibers (Figs. 8.53,
8.54, and 8.55)

Comparison discussion : Here we have type 1 collagen fibers isolated from tissue.
The negative-staining technique makes it possible to see the fiber and its periodicity
(Fig .8.53) . Rotary shadowing also reveals the microfilaments or globular proteins
that can be associated with the fiber (Fig. 8.54) . This technique is especially inter-
esting when working with molecules of small dimensions (other types of collagen,
DNA, RNA, and other fibrillary proteins). The freeze-fracture technique yields an
image “in relief,” with clearer contours that favor measurements. It also makes it
possible to view the globular proteins that might be associated (Fig 8.55) . It is
possible to perform immunolabeling on the freeze fracture.

Fig. 8.53 Reconstituted
collagen fiber in negative
staining. ( A. Rivoire
EZUS-UCB Lyon 1 )

Fig. 8.54 Collagen fiber with
rotary shadowing. ( B. Burdin
CT µ UCB-Lyon 1 )