Microscope

• Microscope pt1

  TEM stands for transmission electron microscope

  • Uses electrons to form an image
  • Electrons that pass through specimen are detected
  • Magnification is up to 1,000,000
  • Resolution is 0.2nm
  • Only dead or non living specimens can be used
• Microscope pt2

  SEM stands for scanning electron microscope

  • Uses electrons to form an image
  • Electrons that are reflected from the surface on the specimen are detected
  • Magnification up to 1,000,000
  • Resolution is 3.2 nm
  • Only dead or non living specimens
• Microscope pt3

  LSCM stands for laser scanning confocal microscopes

  • Uses a large beam to scan an object pixel by pixel
  • Creates 3D and 2D images
• Stains pt1

  Stains are used to

  • Make cells visible
  • Increase contrast
  • Identify cell components
• Stains pt2

  Stains that are used include:

  • Methylene blue stains nucleus
  • Crystal violet makes bacteria purple
  • Eosin red stains cytoplasm
  • Congo red stains outside of cells
• Light microscope

  Uses light to form an image as light passes through or reflects from surface of the specimen seen

  • Magnification to 2000
  • Resolution 200 nm
  • Living and non-living specimens can be observed
• What is the formula for magnification in microscopy?

  • Magnification = image size / size of real object
• What does resolution refer to in microscopy?

  Resolution is the ability to distinguish between two objects that are very close together.
• What does higher resolution in microscopy indicate?

  Higher resolution means more detail.
• Magnification is the number of times greater the size of the image is than the size of an object
• A stage micrometer is a slide that has actual scales etched onto it. It's used to calibrate the eye piece graticule
• An eye piece graticule has arbitrary units as a scale for measurement and is used to measure the specimen
• Advantage of using light microscope

  • Cheap
  • Easy to use
  • Portable
• Disadvantages of using light microscope

  • Not a good resolution
  • Low magnification
• Advantages of using TEM

  • Shows small organelles
  • High magnification and resolution
• Disadvantages of using TEM

  • Requires a vacuum
  • Expensive
  • Requires a high level of skill
• Advantages of using SEM

  • Shows small organelles
  • Has a high magnification and resolution
• Disadvantages of using SEM microscope

  • Expensive
  • High level of skill needed to use
• • SEM and LSCM produce 3D images
  • TEM , light and LSCM produce 2D images