Goal

This practical gives you insight in how a microscope works and how you can operate it.

Microscope Parts

Let’s start by taking a closer look at the parts of a microscope.

Microscope Parts - CC BY SA 4.0 Microscope Parts - Published by Waag under Creative Commons BY SA 4.0 license

The final magnification of a microscope is equal to the multiple of the magnification of the lens and the objective. In the Open Wetlab microscopes the lens magnifies 10x and there are objectives for 4x, 10x, 40x and 100x magnification.

The focusing mechanism consists of two wheels. The outer wheel is just to make big movements. The inner wheel is used to focus by smaller steps.

Underneath the stage a third lens setup can be found. This is the condenser. Using these lenses you can focus the light on the object. Using the diaphragm you can vary the intensity of the light too. Lower the intensity to increase the contrast.

Operating the Microscope

  1. Switch on the light.
  2. Turn the focusing mechanism until the stage is in its lowest position.
  3. Put the microscope slide on the stage.
  4. Select the 10x objective from the revolving nosepiece.
  5. Look through the lens and raise the stage by turning the focus wheel until a clear image appears.
  6. You may need to decrease the light intensity to enhance the contrast.
  7. Use the inner wheel to focus a bit more.
  8. You may switch the object. Adjust the focus by turning the inner wheel if necesary.

Changing Object

  1. Select the 10x objective from the revolving nosepiece.
  2. Lower the stage all the way down.
  3. Change the object.

Quit using the Microscope

  1. Switch of the light!!
  2. Select the 10x objective.

Back to BHA3 - Class 4