Application of ion etching to immunoscanning electron microscopy

Area of Science:

• Cell Biology
• Microscopy Techniques
• Immunohistochemistry

Background:

• Correlating light microscopy (LM) and electron microscopy (EM) is crucial for understanding cellular ultrastructure.
• Immunolabeling techniques enhance specificity but can be challenging to integrate with high-resolution EM.

Purpose of the Study:

• To develop a method for sequential light and scanning electron microscopic observation of the same immunolabeled semithin section.
• To optimize ion etching parameters for preserving immunolabeling while enabling ultrastructural visualization.

Main Methods:

• Semithin sections of rat pancreas embedded in LR white resin were used.
• Mild ion etching (IE) was applied before and after immunohistochemical staining (anti-insulin, immunogold, silver enhancement).
• Scanning electron microscopy (SEM) with secondary electron imaging was employed for ultrastructural analysis.

Main Results:

• Immunohistochemical staining clearly identified pancreatic B cells and insulin.
• Mild IE enabled visualization of secretory granule cores labeled with gold-silver particles in B cells via SEM.
• The method allows correlation of LM observations with high-resolution SEM images.

Conclusions:

• The described method successfully integrates LM and SEM for analyzing immunolabeled samples.
• It is suitable for detecting substances using immunogold labeling and provides high-resolution correlative imaging.
• This technique facilitates detailed ultrastructural observations of specific cellular components.