Microscopy

• What’s the aim of the microscope experiment?

  • To use a light microscope to observe, draw and label a selection of plant and animal cells, including a magnification scale
• How to prepare a microscope slide?

  • Specimens must be prepared on a microscope slide to be observed under a light microscope
  • This must be done carefully to avoid damage
  • The most common to observe are cheek cells or onion cells
  • Stains are used to highlight structures within cells - methylene blue is used to stain cheek cells and iodine for onion cells
• How to do the experiment

  Onion cell

  
• How to use a light microscope? Steps 1-4

  1. Clip the side carefully onto the stage
  2. Ensure the lowest powered objective lens is over the slide
  3. Use the coarse adjustment knob to bring the stage up to just below the lens
  4. Look down the eyepiece and gradually move the stage downwards using the coarse adjustment knob and stop when the image is roughly in focus
• How to use a light microscope steps 5-6?

  5. To bring the image into focus, adjust the fine-adjustment knob until a clear image is obtained

  6. To observe an image with a higher magnification, change the objective lens to a higher power and readjust the stage using the coarse and fine adjustment knob
• Label the microscope

  Microscope

  
• What are the rules for biological drawings?

  • Always draw what you see with a sharp pencil using clear, unbroken lines
  • All structures should be drawn in proportion
  • Label all features using straight, uncrossed lines
• How should biological cell drawings look?

  cells