Spatial visualization of junctional complexes by backscattered electron imaging and silver staining

Area of Science:

• Cell Biology
• Microscopy Techniques
• Histology

Background:

• Junctional complexes are vital for tissue integrity and cell communication.
• Observing these structures typically requires tissue sectioning or dissociation, which can introduce artifacts.
• Existing imaging methods have limitations in visualizing junctional complexes within intact tissue blocks.

Purpose of the Study:

• To develop and present a new method for observing junctional complexes in intact tissue blocks.
• To utilize backscattered electron imaging in scanning electron microscopy for this purpose.
• To enable visualization of junctional complexes without tissue dissociation or sectioning.

Main Methods:

• A modified silver staining technique, originally for nucleolar organizer regions, was applied 'en bloc' after formalin or glutaraldehyde fixation.
• Backscattered electron imaging in scanning electron microscopy was employed.
• The method was tested on liver, jejunum, and urinary bladder tissues.

Main Results:

• The silver staining effectively revealed junctional complexes in the studied tissues.
• Backscattered electron imaging allowed clear observation of these complexes on the surface of intact superficial cells.
• The technique provided visualization 'by transparence' in non-dissociated and non-sectioned tissues.

Conclusions:

• This method offers a valuable approach for studying junctional complexes in their native tissue context.
• It facilitates the observation of junctional complexes without the need for dissociation or sectioning, preserving tissue architecture.
• The technique enhances the understanding of cell-cell interactions and tissue structure through improved imaging capabilities.