Transmission electron microscope type EMC, made by the RCA Corporation, 1944

Unlike optical microscopes that magnify using visible light, electron microscopes use a beam of tiny particles called electrons to produced magnified images. They are capable of magnifications much greater than light-based microscopes, and have been used for visualising objects at the celluar and even atomic scale.

The Radio Corporation of America (or RCA) were one of the first to commercialise electron microscopes in the 1940s, this particular instrument being an early example that was used at Queen University Belfast. Electron microscopes are now common in research institutions, as well as other sites of scientific and medical work such as hospitals.