1. A device which uses electrons, generally focused by electron lenses, to magnify tiny objects onto a fluorescent screen or photographic plate.

It provides much greater plowers of magnification than an optical microscope; that is, up to 1,000,000 times actual size without loss of sharpness and degree of contrast in the image.

2. An electronic instrument that scans cell and tissue sections with a beam of electrons instead of visible light.

The specimen is stained with electron-opaque dyes and with its high magnification power, it creates an image that can be photographed or viewed on a florescent screen.

3. A device for directing streams of electrons by means of electric and magnetic fields in a manner similar to the direction of visible light rays by means of glass lenses in an ordinary microscope.

Since electrons carry waves of much smaller wavelengths than light waves, correspondingly greater magnifications can be obtained.

The electron microscope will resolve details from 1,000 to 10,000 times finer than the optical microscope and images can be studied on a fluorescent screen or recorded photographically.