Comparisons of Techniques - Sample Preparation Topic for Transmission Electron Microscopy - page 228

Fig. 8.48 TEM image of the
same tissue with
immunolocalization of
hyaluronic acid-based
proteins conducted on an
ultrafine section prepared
using chemical fixation,
cryo-substitution and cryo-
embedding and
ultramicrotomy at room
temperature. ( M. Haftek,
Dermatologie UCB-Lyon 1 )
3.4.4 Comparison of “Immunolabeling,” “Ultramicrotomy,”
and “Cryo-ultramicrotomy” Techniques
Techniques: Ultramicrotomy (“Techniques” Chapter 4, Section 4),
Cryo-ultramicrotomy (“Techniques” Chapter 4, Section 5), and Immunolabeling
(“Techniques” Chapter 6, Section 4)
Bulk material: normal human dermis
Comparison discussion : Both figures show spiny junctions located between two
keratinocyte epidermal cells. The same immunolabeling is conducted on both types
of preparation. Here, an inter-keratinocyte epidermal proteoglycan is labeled with an
antibody coupled to 10-nm gold particles. In the first case, the tissue has been chem-
ically fixated and embedded at low temperature (PLT method) in Lowicryl K4M.
The sections obtained using ultramicrotomy have been immunolabeled (Fig. 8.49) .
In the second case, the tissue was fixated only using paraformaldehyde before being
Fig. 8.49 Immuno-
localization of an epidermal
proteoglycan in the junction
zone (j) of two keratinocytes.
Immunolabeling on the
ultrafine section after PLT
embedding and
ultramicrotomy. ( M. Haftek,
Dermatologie UCB-Lyon 1 )