Microscope Types and Parts

Microscope Types

• Light microscopes use optical lenses and light to magnify images

Parts of a Light Microscope

• Ocular Lenses (Eyepieces):

  • One or two removable lenses
  • Used to view the specimen
  • Typically have 10X magnification
  • May have a pointer to identify specific areas

• Head (or Body Tube):

  • Connects the eyepiece to the objective lenses

• Arm:

  • Straight or curved vertical part
  • Connects the body tube to the base
  • Used to carry the microscope

• Base:

  • Supports the microscope
  • Contains the light source

• Light Source (Illuminator):

  • Sends light upwards through the condenser lens
  • Directs light onto the specimen
  • Older microscopes used a mirror

• Revolving/Rotating Nose Piece:

  • Holds the objective lenses
  • Allows switching between different objective magnifications

• Objective Lenses:

  • Typically 3 or 4
  • Mounted on the revolving nosepiece
  • Common magnifications: 4X (scanning), 10X (low), 40X (high), and 100X (oil immersion)

• Condenser:

  • Lens below the stage
  • Focuses light from the illuminator through the stage hole

• Iris Diaphragm:

  • Located beneath the condenser
  • Adjustable dial to control the amount of light reaching the specimen

• Stage:

  • Flat platform
  • Holds the slide
  • Allows movement of the slide

• Stage Clips:

  • Secure the slide on the stage

• Coarse Adjustment Knob:

  • Used for initial focusing, primarily with low power

• Fine Adjustment Knob:

  • Used for precise focusing, especially with higher magnification

Calculating Magnification

• Multiply the magnification of the ocular lens by the magnification of the objective lens to find the overall magnification

Electron Microscope

• Electron microscopes use an electron beam
• Electromagnets act as lenses
• Two types: Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM)