Described by the Nobel Society as "one of the most important inventions of the century," the electron microscope is a valuable and versatile research tool. The first working models were constructed by German engineers Ernst Ruska and Max Knoll in 1932, and since that time, the electron microscope has found numerous applications in chemistry, engineering, medicine, molecular biology and genetics.

Electron microscopes allow molecular biologists to study small structural details related to cellular function. Using an electron microscope, it is possible to observe and study many internal cellular structures (organelles). Electron microscopy can also be used to visualize proteins, virus particles, and other microbiological materials.

At the turn of the twentieth century, the science of microscopy had reached an impasse: because all optical microscopes relied upon visible light, even the most powerful could not detect an image smaller than the wavelength...