Light Microscopy

• Name all feature of a light microscope.

  A) eyepiece

  B) objective

  C) coarse

  D) fine

  E) light

  F) stage

  G) slide

  
• What is light microscopy used for?

  To observe small structures in detail
• How does a light microscope magnify an object?

  Through two glass lenses: objective and eyepiece
• What is the first step to observe cells through a microscope?

  Move the stage to its lowest position
• What should you select after moving the stage down?

  Select the objective lens with the lowest magnification
• Where do you place the slide with cells on it?

  On the stage of the microscope
• What should you do after placing the slide on the stage?

  Raise the stage to its highest position
• What is the purpose of the coarse focus knob?

  To lower the stage until the object is visible
• What happens when you first see your object through the microscope?

  It will normally be blurred
• What should you do after seeing a blurred object?

  Turn the fine focus knob slowly
• How can you see cells in greater detail?

  Switch to a higher magnification objective lens
• What should you use to bring the object into clear focus again?

  Use the fine focus knob
• What are the steps to observe cells through a microscope?

  1. Move the stage to its lowest position.
  2. Select the objective lens with the lowest magnification.
  3. Place the slide on the stage.
  4. Raise the stage to its highest position.
  5. Lower the stage slowly using the coarse focus knob.
  6. Turn the fine focus knob until the object is clear.
  7. Switch to a higher magnification lens for more detail.
• What is the formula to calculate total magnification in a microscope?

  total magnification = eyepiece lens magnification x objective lens magnification
• Why do scientists stain cells?

  To make colorless cells easier to observe
• What are some common stains used in microscopy?

  • Methylene blue: highlights animal cell nuclei
  • Iodine: highlights plant cell nuclei
  • Crystal violet: stains bacterial cell walls
• What are the steps to apply a stain to cells on a slide?

  1. Place cells on a glass slide
  2. Add one drop of stain
  3. Place coverslip on top
  4. Tap coverslip gently to remove air bubbles