Uses of Electron Microscope Essay Example | Topics and Well Written Essays - 6250 words

Uses of Electron Microscope - Essay Example The light microscope was invented in the 17th century from the Galilean telescope. Antony van Leeuwenhoek, a Dutchman developed one of the early microscopes which consisted of a powerful convex lens and an adjustable holder for the object being studied. This instrument had a magnifying power of 400x and protozoa, spermatozoa, bacteria and shape of the red blood cells were discovered by Leeuwenhoek (FEI company, 2008). This microscope had only one lens and was called a single microscope. An improvement on this was compound microscope wherein another convex lens was added to magnify the image produced by the first lens. A modern light microscope has a magnification of as high as 1000x and thus enables resolution of objects separated by 0.0002mm (FEI Company, 2008). The resolving power of light microscope had 3 limiting factors: lenses, quality of lenses and the wavelength of light used for illumination. Some improvements in the light microscope were made using these aspects. Blue or ul traviolet light with shorter wavelength gave a small improvement. Further improvement in the resolution was noticed when the specimen and the front of the objective lens were immersed in a medium like oil with high refractive index (FEI Company, 2008). As early as the middle of 19th century, microscopists realized that structures less than half a micrometer could not be resolved with a light microscope. At the same time, researchers had hinted at the possibility of improvement in the resolution of the microscope using electrons rather than light. This is because accelerated electrons behave in a vacuum just like light, they travel in straight lines and have a wavelength which is about 100,000 times smaller than that of light.