How to observe cells under a microscope

In a nutshell

Organisms are all made up of cells. Cells are very small, so a light microscope is needed to be able to see them. A light microscope is a piece of equipment that uses visible light and different lenses to magnify objects, allowing you to see them. 

Cells

Cells are the building blocks of all living things, including animals and plants. Cells are very small so they can only be seen under a microscope. Sometimes, they need to be stained with a coloured dye to help you see them.

Light microscope

Some objects are too small to be seen with the naked eye but they can be seen with a light microscope. This is a piece of equipment that uses visible light and different lenses to magnify objects, allowing you to see them. The light will shine through the object and into the objective lens. Then it passes through the eyepiece lens which allows you to see the object.

Parts of a microscope

1. Eyepiece: The eyepiece is what you look through to see the magnified image. The eyepiece contains the eyepiece lens which magnifies the specimen to produce the image you can see.
   
   
2. Body tube: The body tube separates the eyepiece and objective lenses.
   
   
3. Rough focusing knob: The rough focusing knob is used to move the stage to bring the image into focus.
   
   
4. Fine focussing knob: The fine focusing knob is used to bring the image into focus after the rough focusing knob is used.
   
   
5. Objective lenses: The objective lens magnifies the specimen. There are usually three lenses with increasing power. The highest-powered lens will create a greater magnification.
   
   
6. Handle: The microscope should be held by the handle.
   
   
7. Stage: The stage is where the slide is placed.
   
   
8. Mirror: The mirror should be angled towards a light source and up through the hole in the stage. This provides the light that enables you to see the image.

Note: In some microscopes there will be a lightbulb instead of a mirror.

Using a light microscope

It's important to be able to use a microscope so you can investigate objects that are too small to be seen with the naked eye.

​​procedure

1. ​You must be careful with microscopes and hold them by the handle.
   
   
2. If the light microscope has its own light source then you can put it anywhere, but if it uses mirrors it must be placed near a window or a lamp. The mirror should be angled towards the light and up through the hole in the stage.
   
   
3. The object should be put on a glass slide and the glass slide should be placed on the stage. Clip the glass slide in place on the stage.
   
   
4. Rotate the lenses to select the lowest power objective lens.
   
   
5. Turn the rough focusing knob to move the objective lens to the slide. It is best to focus by moving the stage downwards as this reduces the chance of the slide breaking.
   
   
6. Look down the objective eyepiece lens and use the fine focusing knob to bring the object into focus.
   
   
7. If you need more magnification then use a higher power objective lens.
   
   
8. Refocus the microscope using steps 5 and 6.