Microscopes

• Magnification

  How much bigger an object appears than its actual size.
• Resolution

  How well a microscope can distinguish between two points that are close together.
• Light microscopes

  • Use light
  • Maximum resolution of 0.2 mm (low)
  • Used to look at whole cells or tissues
  • Maximum magnification of x 1500
• Transmission electron microscope

  • Uses electromagnets to focus a beam of electrons that is transmitted through the specimen
  • Produces black and white 2D images
  • High resolution of 0.5nm
  • Maximum resolution of x 2 million
  • Used to look at organelles
• Scanning electron microscope

  • Scan a beam of electrons accross the specimen
  • Electrons knock off the specimen and are gathered by a cathode ray to forman image
  • 3D images that show the surface of the specimen
  • Lower resolution than TEM
• Laser scanning confocal microscopes

  • Type of light microscope
  • A laser scans the specimen
  • Can view different layers of the specimen
  • Higher resolution than a light microscope
  • 3D images with differential staining