Microscopes

Microscopes

Types of Microscopes You Need to Know

There are two important types of microscopes:

  1. Light Microscope
  2. Electron Microscope

A light microscope is great for practical experiments, like examining onion cells or your own cheek cells. But what sets these two types apart? Let’s explore the key differences:

A comparison of light and electron microscopes in a table
A light microscope showing the key parts of a light microscope
Parts of a light microscope

Microscopes and What They Reveal

Microscopes allow us to explore the fascinating details of cells and their parts, known as organelles.

  • A light microscope is perfect for observing individual cells and larger organelles, like the nucleus or mitochondria.
  • An electron microscope lets us see much finer details, including smaller organelles like ribosomes or the internal structure of the mitochondria.

What are Organelles?
Just as our bodies have organs to perform specific tasks, cells have organelles – their own “mini-organs.”

What is Resolution?
Resolution is the ability to distinguish two separate points in an image. A higher resolution means a sharper and clearer image.

Observing Cells Under a Microscope

You can observe the structures of animal cells or plant cells with two simple practicals:

  1. Looking at Onion Cells

    What to Look For:

    • Cell walls
    • Cytoplasm
    • Nucleus

  2. Examining Cheek Cells

    What to Look For:

    • Cell membrane
    • Cytoplasm
    • Nucleus

Tip: Stains like iodine or methylene blue make it easier to see the cell structures!

1. Looking at Animal Cells Under a Microscope

Method

  1. Chew gently on the inside of your cheek for about 2 minutes, but be careful not to draw any blood.
  2. Using a sterile swab, gently swab the inside of your cheek.
  3. Transfer the cells by rubbing the swab onto the centre of a microscope slide.
  4. Add 1 or 2 drops of Methylene Blue (this helps to stain the cells, making them easier to see).
  5. Carefully place a cover slip over the stained cells.
  6. Using a microscope, examine the cheek cells and try to draw and label what you see.
Animal cells, from a cheek, under a microscope when stained with methylene blue and the three organelles you can see

2. Looking at Plant Cells Under a Microscope

Method

  1. Either you or your teacher should cut a small square section of an onion.
  2. Using tweezers, carefully peel away the inner layer of the onion. This layer should be very thin, ideally just a single layer of cells.
  3. Transfer the cell sample onto your microscope slide, making sure it is flat.
  4. Add 1 or 2 drops of Iodine solution (this stains the cells and makes them easier to see).
  5. Carefully place a cover slip over the stained onion cells.
  6. Using a microscope, look at the onion cells and try to draw and label what you can see.
Plant cells, from an onion, under a microscope when stained with iodine and the three organelles you can see

* You may be asked to work out the magnification or actual size of the cheek cell.