COMPOUND MICROSCOPE

• Magnification


  The result of two lenses: the objective and the ocular
• Objectives


  • Scanning Power
  • Low Power
  • High-Dry Power
  • Oil Immersion
• Scanning Power objective


  • Shortest objective with red stripe
  • Magnifying power of 4X
• Low Power objective


  • Second shortest objective with yellow stripe
  • Magnifying power of 10X
• High-Dry Power objective


  • Intermediate length objective with blue stripe
  • Magnifying power of 40X
• Oil Immersion objective


  • Longest objective with white or black stripe
  • Magnifying power of 100X
• Ocular or Eyepiece


  Located at the end of the bodytube, has a magnification power of 10X
• Total Magnification


  Determined by multiplying the power of the objective by the power of the ocular
• Compound Microscope


  • An upright microscope that uses two sets of lenses (a compound lens system) to obtain higher magnification than a stereo microscope
• Light Microscope


  Specimen is observed using visible light
• Light Source


  • Incandescent bulb, toggled on by switch on base; ensure microscope is plugged and power switch is on before use
• Stage


  • Flat area for placing slides, secured by stage clips for stability
• Slide Movement


  Controlled by two turning knobs below the stage, for left-to-right and front-to-back movements
• Iris Diaphragm


  For illumination, located below the stage; controls light entering condenser for contrast and depth of field; close diaphragm for low power objective, open for higher power
• Refraction


  Occurs when light passes from one density to another; refracted light can be lost, impacting visibility
• Immersion oil and oil-immersion objectives

  Used to mitigate refraction
• Focus Adjustment


  • Coarse and fine adjustment knobs located at the side of the microscope; coarse knob adjusts the vertical level of stage, fine knob for fine-tuning of image
• Depth of Field


  The vertical distance in focus at any one time; decreases with higher magnification, resulting in a thin horizontal slice of focus
• Field of View


  An area of sample visible at any one time; decreases with increased magnification
• Parfocal Objectives


  The vertical distance in focus at any one time; decreases with higher magnification, resulting in a thin horizontal slice of focus
• It is important to observe individual cells under the microscope
• It is important to distinguish observed objects from artifacts or contaminants introduced into the slide
• Universal Precautions


  • No one comes in contact with your body fluids. Properly dispose of any material that is contaminated with your body fluid immediately.
  • Do not come in direct contact with another person's body fluids. Use gloves if needed.
  • Always wear gowns, gloves and safety glasses when engaging in risky laboratory procedures such as obtaining or handling blood products