Observing in Biology

Many of the interesting things in biology are very small and delicate. Our eyes need help to be able to see them properly. Our fingers are too big so we need tools to handle them carefully.

Picking up small specimens

If they are solid use forceps, do not use your fingers.

If they are in water use a dropping pipette.

Observing Small Specimens

First of all make sure that you have enough light. Use a bench lamp.

Using a hand lens

This magnifies about ten times; we write X 10.

Keep the lens close to your eye (about 8 cm). Bring the specimen that you are observing up to the lens or bend down to look at the specimen.

Using a binocular microscope

The binocular microscope usually magnifies by x20. We use both eyes which gives us a clear three-dimensional view.

To use the binocular microscope follow the instructions:

First choose the background that you want to use. A dark specimen is more easily observed against a white background and a pale specimen is more easily observed against a black background.

Put your specimen under the microscope and illuminate it with a bench lamp. Raise the microscope until you can see the specimen approximately in focus. Now lock the microscope in place. Finally focus precisely, using the focusing knob.

You may also find that the eye-pieces of your binocular microscope are too far apart or too close together. These can be moved to suit your eyes.

• Observing very small specimens
• Calculating the magnification on a compound microscope
• Making a slide with a coverslip
• Looking at the slide using the microscope
• Question on the use of the Microscope
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