microscopy

• Microscopy


  The use of microscopes
• How light microscopes work


  1. Light from the room hits the mirror

  2. Reflected upwards through the object

  3. Passes through the objective lens

  4. Passes through the eyepiece lens

  5. Into the eye
• Object


  The real object or sample that you're looking at
• Image


  The image that we see when we look down the microscope
• Magnification


  How many times larger the image is than the object
• Magnification = image size / object size
• Resolution


  The shortest distance between two points on an object that can still be distinguished as two separate entities
• Higher resolution


  More details can be seen, less blurry the image
• The images have the same magnification (100x) but different resolutions
• Light microscopes


  Microscopes that use light, small, easy to use, relatively cheap
• Resolution of light microscopes


  Limited to 0.2 micrometers, any details less than 0.2 micrometers apart will appear blurry
• What light microscopes can be used to see


  • Individual cells like onion cells
• Electron microscopes


  Really big, very expensive, hard to use, only used by scientists in laboratories
• Resolution of electron microscopes

  0.1 nanometers, 2000 times better resolution than light microscopes
• What electron microscopes can be used to study


  • Sub-cellular structures like mitochondria
• This image of a plant cell was taken with an electron microscope and shows the nucleus and mitochondria
• Light microscopes


  Limited resolution, cannot see sub-cellular structures
• Electron microscopes


  High resolution, can see sub-cellular structures