Cells and Microscopes

• Light microscope

  • They use beams of light and lenses to magnify a living object to create an image.
• Electron microscope

  • Has a higher magnification
  • Has a very high resolution 
  • Expensive
  • Need electrons to pass the image
  • More detailed when it comes to viewing cells
• Microscopes magnify images (make them look bigger) and allow things to be seen in more detail. Light microscopes work by passing light through the specimen (the sample you're looking at). They let you see subcellular structures, like nuclei and chloroplasts. 
• How to use a light microscope to view cells

  1. Prepare specimen

  2. Place specimen on slide

  3. Add stain if needed

  4. Place cover slip

  5. Clip slide onto microscope stage

  6. Select low-powered objective lens

  7. Focus using coarse and fine adjustment knobs

  8. Swap to higher-powered lens if needed
• Specimen


  • Needs to let light through it
  • If thick, take a thin slice
• Slide


  A strip of clear glass or plastic
• Mountant


  A clear, gloopy liquid used to secure the specimen in place
• Cover slip


  A square of thin, transparent plastic or glass
• Different stains are used to highlight different structures
• The cover slip is placed at one end of the specimen and carefully lowered onto the slide
• The prepared slide is clipped onto the stage of the microscope
• The lowest-powered objective lens is selected first
• USE OF MICROSCOPE

   (practical and simplified ver)

  • Get a sample and take a thin slice of it, then put it into a slide.
  • Put a drop of iodine ( for plant cells) or methylene blue (for DNA/human cells). 
  • Put another smaller slide on top of the specimen, then use a needle to press it together and prevent bubbles, then gently place the slide on the microscope.
  • Use the eyepiece to see the specimen/cell.
  • Adjust the stage of the microscope and the magnification/objectifying lenses to see the specimen..
• Focusing the microscope

  1. Move stage up until slide is just underneath objective lens

  2. Move stage down until specimen is nearly in focus

  3. Adjust focus with fine adjustment knob until clear image
• Higher-powered objective lenses can be used for greater magnification