The Microscope

This lesson covers: 

  1. The different parts of a light microscope
  2. How to properly set up and use a light microscope

Parts of a light microscope

A light microscope uses lenses to magnify tiny objects. We call the tiny object the 'specimen' when it is being viewed using a microscope.

Diagram showing the parts of a light microscope including eyepiece lens, objective lens, body tube, stage, light source, coarse focus knob, and fine focus knob.

The main parts are:

  • Eyepiece lens - The lens you look through that initially magnifies the specimen.
  • Objective lenses - These magnify the specimen more, and allow the magnification to be changed.
  • Body tube - This holds the lenses in place.
  • Stage - This supports the slide with the specimen.
  • Mirror/light - These ensure there's enough light to see the specimen.
  • Coarse and fine focus knobs - These move the stage up and down to adjust the focus.

Using a light microscope

To use a microscope correctly, follow these steps:

  1. Carry it with care, using both hands.
  2. Position it near a window or lamp for adequate lighting and angle the mirror to direct light upwards.
  3. Secure the slide on the stage with the clips, ensuring the specimen side faces up.
  4. Look through the eyepiece and adjust the focus using the knobs to get a clear, magnified view.
  5. Increase magnification by rotating the nosepiece to switch between lenses.


Note: Always adjust the focus so the objective lenses move away from the slide first to avoid damaging the slide or microscope.