# Accomplishments of “Old-Fashioned” Electron Microscopy in the Period of Dominance of Immunofluorescent Methods

## TL;DR

This review highlights how electron microscopy can reveal cellular details and unexpected biological phenomena that other methods miss.

## Contribution

The paper presents novel findings on cell death, organelle reorganization, and cytoskeleton roles, enabled by electron microscopy techniques.

## Key findings

- Electron microscopy revealed unexpected results in immunolabeling interpretation.
- A new method for identifying cells with mitochondrial disorders and necrosis-like death was developed.
- The sequence of organelle reorganization in dying cells was observed.

## Abstract

The goal of this review is to bring to the attention of the scientific community the opportunities of transmission electron microscopy for analyses of biological subjects and resolving complicated cases of data interpretation. Although procedures for electron microscopy are in general more elaborate (particularly for simultaneous immunolabeling of multiple antigens) compared to fluorescent microscopy, they can help view cellular morpho-functional features undetectable using other methods. In this review, we consider several unexpected and serendipitous discoveries made in our laboratory and fulfilled using unique opportunities provided by electron microscopy of ultrathin sections. We are deliberating the following topics: interpretation of unusual results of immunolabeling; a novel method for in situ identification of cells undergoing mitochondrial disorder and necrosis-like death; the sequence of organelles’ reorganization in dying cells; simultaneous rupture of nuclear and plasma membranes in migrating neurons; and the role of cytoskeleton in lateral expansion of the cerebral cortex.