• Light microscope
• Microscope slides
• Cover slips
• Specimen (onion peel, cheek cells, leaf tissue, or pond water)
• Dropper
• Staining solution (iodine solution or methylene blue)
• Lens paper or soft cloth

Before placing a specimen on the microscope, you must prepare it properly:

1. Clean the slide – Wipe the slide with a clean cloth to remove dust.
2. Place the specimen – Using forceps or your fingers, place a thin piece of the specimen (like onion peel) in the center of the slide.
3. Add a drop of stain – Use a dropper to add one or two drops of iodine solution or methylene blue. This helps to color the cell structures so they become visible.
4. Cover with a cover slip – Hold the cover slip at a 45° angle and lower it gently onto the specimen to avoid trapping air bubbles.
5. Remove excess liquid – Use blotting paper to absorb any extra liquid around the cover slip.

Follow these steps to observe your specimen correctly:

1. Position the microscope – Place the microscope on the laboratory bench, away from the edge. Carry it with both hands: one hand on the arm and the other supporting the base.

2. Select the low-power objective – Turn the revolving nosepiece to align the low-power objective (marked 4x or 10x) with the eyepiece. You should hear a click when it locks into place.

3. Adjust the mirror or light source – Turn the mirror to reflect light through the diaphragm and up through the specimen. If using an electric microscope, switch on the light source.

4. Place the slide – Position your prepared slide on the stage. Secure it with stage clips so it does not move.

5. Focus with coarse adjustment – Look through the eyepiece and slowly turn the coarse adjustment knob to lower the tube until the objective lens is close to the slide. Then slowly raise the tube until the specimen comes into view.

6. Focus with fine adjustment – Once you see a blurred image, use the fine adjustment knob to sharpen the image until it is clear.

7. Observe and draw – Look carefully at the specimen. Identify the main cell structures visible and draw what you see in your notebook.

8. Switch to higher power (if needed) – For more detail, rotate the nosepiece to the medium-power objective (40x) and use the fine adjustment knob only. Never use the coarse adjustment knob with higher power lenses.

When observing cells, you should identify these structures:

Plant cells (onion peel):

• Cell wall – outer rectangular boundary
• Cell membrane – just inside the cell wall
• Cytoplasm – jelly-like substance filling the cell
• Nucleus – dark-stained circular structure, often near the edge
• Vacuole – large clear space in the center

Animal cells (cheek cells):

• Cell membrane – outer boundary
• Cytoplasm – surrounds the nucleus
• Nucleus – usually in the center, stained dark
• Mitochondria – tiny dots in the cytoplasm

• Always start with the low-power objective to find your specimen before switching to higher power.
• Never use the coarse adjustment knob when using the high-power objective – you may crush the slide.
• Keep both eyes open while looking through the eyepiece.
• If the image is too dark or too bright, adjust the diaphragm.
• Always place a cover slip over wet specimens to protect the objective lens.
• Clean the lenses with lens paper only – never use your fingers or regular cloth.

• Placing the specimen too thick – light cannot pass through
• Air bubbles trapped under the cover slip
• Forgetting to add stain – cells may appear invisible
• Moving the slide while focusing
• Using the wrong objective lens for focusing

In Tanzania, farmers and agricultural officers use microscopes to check plant samples for diseases. For example, if a tomato plant's leaves are turning yellow, a technician can examine leaf cells under a microscope to identify whether a fungus or bacterium is causing the problem. This helps farmers apply the right treatment, saving crops and increasing harvest yields. Similarly, students learning this skill in biology class are preparing for careers in medicine, agriculture, and environmental science where microscopic examination is routinely used.