elektronmikroskoopi

Elektronmikroskoopi, often abbreviated as EM, is a microscopy technique that uses a beam of accelerated electrons as a source of illumination to examine a sample at very high magnification. This allows for resolutions far beyond what is possible with light microscopes, enabling the visualization of structures at the atomic and molecular level. The electron beam interacts with the sample, and the resulting scattered or transmitted electrons are detected to form an image.

There are two main types of electron microscopes: transmission electron microscopes (TEM) and scanning electron microscopes (SEM). TEMs pass the electron beam through an ultra-thin specimen, and the resulting image reveals internal details of the sample's structure. SEMs, on the other hand, scan a focused electron beam across the surface of a specimen, and the detected secondary or backscattered electrons create an image of the surface topography.

Electron microscopy requires samples to be prepared in specific ways, often involving fixation, dehydration, and staining with heavy metals to enhance contrast. Due to the vacuum required for electron beams to travel, biological samples typically need to be fixed and preserved. Applications of electron microscopy are vast and span across various scientific disciplines, including materials science, biology, medicine, and nanotechnology, for studying cell structures, viruses, defects in materials, and nanoscale phenomena.