Microscopy bio paper 1

• Microscopy


  The use of microscopes to study small objects and structures
• Light microscope


  • Flight source (mirror)
  • Stage to put microscope slide
  • 3 objective lenses with different magnifications
  • Eyepiece lens with fixed magnification
  • Coarse focusing knob
  • Fine focusing knob
• How light microscope works

  1. Light hits mirror and reflects upwards through object on microscope slide

  2. Passes through one of the objective lenses

  3. Then through eyepiece lens

  4. And into our eye
• Magnification


  How many times larger the image is than the object
• Resolution


  Shortest distance between two points on an object that can still be distinguished as two separate entities (measure of how detailed the image is)
• Light microscopes


  • Easy to use
  • Cheap
  • Rely on light
  • Resolution limited to 0.2 μm
  • Not good enough to study subcellular structures
• Electron microscopes


  • Very expensive
  • Hard to use
  • Use electrons instead of light
  • Max resolution is 0.1 nm
  • Can see smaller details