Methods of Studying Cells

• Light Microscope:

  • Convex glass lenses
  • Low resolution
  • Small magnification
  • Coloured images
  • 2D image
• Magnification = Size of Image / Size of Object
• Resolution is defined as the minimum distance apart that two objects can be distinguished as separate objects in an image. The greater the resolution the more clear the image will be.
• Transmission Electron Microscope:

  • A beam of electrons passes through a thin section of specimen. Areas that absorb the electrons appear darker on the electron micrograph produced.
  • 2D image
  • High resolution
  • Large magnification
  • Greyscale image
• Scanning Electron Microscope:

  • A beam of electrons passes across the surface and scatter. The pattern of scattering builds up a 3D image depending on the contours of the specimen.
  • 3D image
  • High resolution
  • Large magnification
  • Black and white image
• Electron microscopes have to be used in a vacuum so living specimens cannot be observed.