Microscopes: instruments that turn invisible into visible
A microscope is a magnifying instrument that is used to look at objects that are too tiny to be seen by the naked eye. Light microscopes (LM) are commonly used to look at intact cells in the laboratories, they produce images by projecting light beams on the specimen surface and magnifying the image through the use of optical lenses. However, they are not powerful enough to image extremely small organisms such as viruses (about 10x smaller than bacteria) or zoom into the interior of cells. Therefore, nowadays we have much more complex microscopes such as the electron microscopes (EM). In EMs, electron beams are projected onto the specimens and images are magnified with the use of electromagnetic fields.