Essay on Electron Microscopes

Submitted By lynnkerstin97
Words: 713
Pages: 3

Microscopes A microscope is a tool scientist use to see living or non-living things that cannot be seen by the naked eye. There are two main types of microscopes. They are light microscopes and electrons microscopes. Light microscopes produce magnified images by focusing visible light rays. Compound light microscopes allow light to pass through using two lenses to form an image. Electron microscopes produce magnified images by producing beams of electrons. Biologist uses two main types of electron microscopes. Transmission electron microscopes shine a light through a thin specimen. Scanning electron microscopes scan a beam of light back and forth across a specimen. The parts of a microscope are the body tube, arm, eyepiece, revolving nosepiece, objectives, stage, stage clips, diaphragm, course adjustment knob, fine adjustment knob, light source, and base. Knowing the parts of a microscope will defiantly help you when looking at specimens under the microscope. It would help to know how to make a wet mount and how to stain a slide. To make a wet mount you gather a thin slice/piece of whatever your specimen is. If your specimen is too thick, then the coverslip will wobble on top of the sample like a see-saw, and you will not be able to view it under High Power. Place ONE drops of water directly over the specimen. If you put too much water, then the coverslip will float on top of the water, making it hard to draw the specimen, because they might actually float away. (Plus too much water is messy) Place the coverslip at an angle with one edge touching the water drop and then gently let go. Performed correctly the coverslip will perfectly fall over the specimen. To stain a slide you Place one drop of stain on the edge of the coverslip. Place the flat edge of a piece of paper towel on the opposite side of the coverslip. The paper towel will draw the water out from under the coverslip, and the cohesion of water will draw the stain under the slide. As soon as the stain has covered the area containing the specimen, you are finished. The stain does not need to be under the entire coverslip. If the stain does not cover as needed, get a new piece of paper towel and add more stain until it does. Be sure to wipe off the excess stain with a paper towel. Microscopes came from two Dutch glasses makers, Zaccharias Janssen and his son Hans, while experimenting with several lenses in a tube, discovered that nearby objects appeared enlarged. That was the pioneer of the compound microscope and of the telescope. In 1609, Galileo, father of physics and astronomy, heard of these early experiments, worked out the principles of lenses, and made a much better instrument