Making a permanent specimen

Watering can, fountain, stream – can’t wait to investigate the water from your garden or a park? Then take a water sample and let us prepare a specimen for your microscope so that you can take a closer look at what’s swimming around.

All you need to do is take a slide and add one or two drops of your sample with a pipette. Then place a coverslip over the slide. If necessary, press down slightly on the coverslip. You can remove the excess water with filter paper.

Would you like to colour your finished sample? If so, use a drop of ink from a normal ink cartridge, e.g. from your fountain pen. Place the ink on the left or right edge of the coverslip covering the slide. Hold a piece of blotting or filter paper on the opposite edge. As you will see for yourself, the ink will be absorbed and colour the entire sample. Now you are ready to inspect your first specimen – let’s go!

Preparing specimens - thin section

Did you find an interesting leaf during your last walk in the forest that you want to look at more closely under the microscope? If so, there’s much more to look at than just the surface. The inside of your leaf will also have all sorts of exciting things to discover.

Your first observation

Lukas will show you how to make your first microscopic observations a resounding success!

1. Sit in front of your microscope and turn the tube towards you.

2. What would you like to look at first? To begin with, try something like a strand of hair or a pre-prepared specimen. Then place your specimen on the stage. Ensure that there is a sufficient gap between your specimen and the nosepiece, otherwise the lenses may get scratched.

3. Then choose the objective with the smallest magnification and turn it so that it is pointing at your sample. Important: When adjusting the nosepiece, always look from the side to check that there is a sufficient gap between the objective and the specimen. This allows you to better gauge the distance and ensure that you protect the sample as well as the lenses.

4. To adjust the focus, look through the eyepiece and turn the wheel on the side until the object comes into focus.

5. You can now move the slide with your sample back and forth on the stage to get a close-up view of every detail!

6. When you find something interesting, move the objective to the next magnification level. Look again from the side to check that there is a sufficient gap between the slide and the lens. Each objective will bring you closer to your discovery!

7. Finally, don’t forget to enter your exciting observations in your microscope journal.

The structure of a cell

Cells are the building blocks of all living things. You and everything inside you also consists of cells – a mind-boggling number of them! For example, a person weighing 70 kg has about 30 billion cells. Incredible, right? Nature is also made of these tiny structures. Every animal, tree and plant is made of cells. But what does a cell really look like? Let’s take a look in more detail!

Cell membrane – This is the outer edge of the cell and ensures that the cell is an enclosed space.
Cell plasma or cytoplasm – This is the liquid in the cell, which consists primarily of water as well as protein, nutrients, sugar and salts.
Nucleus – This is the largest cell organelle and contains the DNA, the blueprint for the living organism.
Endoplasmic reticulum (ER) – This is located around the nucleus and produces building blocks for the cell, such as proteins.
Golgi apparatus – This ensures that the different building blocks are transported from the ER to the Golgi apparatus and then on to their final destination. You can think of it as a post office.
Vesicle – These function like balloons, in which the building blocks are transported through the cell. They work like postmen who deliver parcels.
Mitochondria – This is the powerhouse of the cell where cell respiration occurs and energy is produced that the cell requires for survival.
Chromoplast – These provide the colour for the flowers and fruits of the plant.
Chloroplasts – These colour the cell green and conduct photosynthesis, i.e. convert carbon dioxide into oxygen.
Vacuole – This is a cavity within the cell that is filled with cell plasma and stores protein as well as toxins/bitter compounds.

Viruses and bacteria

Lukas is feeling a bit under the weather. He feels weak, has a sore throat and no appetite. But why is his body reacting in this way, and to what? In many cases, it is either viruses or bacteria that make life difficult for us with these symptoms. But do you know the difference between these two potential pathogens? That isn’t so obvious, because viruses and bacteria can be found almost everywhere in our daily life. However, they are so small that we can’t see them. Lukas also can’t identify them with his naked eye.

Let’s take a closer look at the differences between bacteria and viruses:

First of all, Lukas discovers than bacteria are much bigger than viruses. On average, they measure 1 micrometre across and are therefore up to 100 times bigger. This means that you can see them under an optical microscope.

Another important difference: Bacteria are living organisms, while with viruses the situation is not so straightforward. Bacteria are the most simple life form. They consist of a cell wall and genetic material as well as ribosomes, cytoplasm and an interior structure When they get into our body, bacteria can carry on dividing and reproducing by themselves, and don’t rely on other cells in our body. Their waste metabolic products make us sick.

Viruses, however, are another story: The question of whether viruses are classed as living organisms is still a matter of debate. However, the following things are clear: The cannot multiply by themselves, and require a host in order to reproduce. Viruses consist only of their genetic material, which is enclosed in a protein shell. They transmit this genetic material to a cell in our body so that the virus can multiply via cell division. If our own body cells are destroyed as a result, we get sick.

And what can Lukas do to get better? Antibiotics usually work against a bacterial infection, while other medicines can be helpful in the event of a viral infection. However, in both cases you should visit a doctor. Meanwhile, rest and enough sleep can never be a bad thing. :-)

Did you know that everyone’s fingerprint is unique? Even identical twins have different fingerprints, although they are otherwise genetically identical. When you get a moment, take a closer look at your fingertips: can you see the fine lines, arches and circles? These are known as papillary lines and are unique to you. We leave an imprint of this unique pattern whenever we touch something. Our fingerprints are particularly visible on smooth surfaces such as glass. They are produced by sweat or grease on your skin. If you view your finger under your microscope, you’ll be able to see the small sweat pores. And because fingerprints are unique to one individual, they are often used as evidence by the police.

Lukas is feeling sad, because someone has stolen the sweets from his tin. He would like to know who it was. He has an idea: he can inspect the fingerprints on the tin and catch the perpetrator!

1. Take your tin or glass and sprinkle some powder over the surface, such as baking powder, cocoa or baby powder.

2. Spread the powder carefully using a thick fine brush. If you look closely, the fingerprint will become visible!

3. Next, take a piece of transparent adhesive tape and stick it carefully over the fingerprint, ensuring that there are no creases.

4. When you remove the adhesive tape, the fingerprint will remain on the tape and you can stick it to a piece of cardboard. If you used a bright coloured powder, choose a dark piece of cardboard. For dark powders, choose a bright piece of cardboard.

5. Now take a fingerprint from your family and friends. Do this in the same way as you did before with the powder and the adhesive tape. Alternatively, take an ink pad and press your finger with the ink onto a piece of paper.

6. You can now compare the fingerprint from the glass or tin with the fingerprints of your family members and friends and hunt down the perpetrator!