The Microscope

Parts of The Microscope

• Microscope stand
• Specimen stage (where the slide lies)
• Nosepiece (holds the objectives)
• Eyepiece (may be 1 or 2)
• Condenser (concentrates the light on the slide)
• Light source
• Objectives
  • 10X objectives magnify the specimen 100 times
  • 20X objectives magnify the specimen 200 times
  • 40X objectives magnify the specimen 400 times
  • 100X objectives magnify the specimen 1000 times (this objective must be used with immersion oil)

Types of Microscopes

• Bright-field Microscope
  When you observe a live sample under brightfield, there is very little contrast between the water and the organism, therefore the organisms do not stand out and are not very distinct because the organisms appear as if they are clear. However, when samples are stained, there is more contrast. Brightfield is not good for observing live samples but is ideal for stained slides.
  
  
• Phase-Contrast Microscope
  Phase-contrast allows you to clearly distinguish organisms and their internal structures. This microscope is more suitable for observing live organism and is the best one to use in water and wastewater laboratories.

Return to Activated Sludge: Microbiology and Process Control.

Additional technical assistance with wastewater treatment plant operations is available from the DNR. Contact Jack Saltes in Madison at (608) 264-6045. For additional help from the DNR, you might also try the Laboratory Certification Program.