practical for microscopes:
cut up an onion, separate it into layers and use tweezers to peel off the epidermal tissue
2. place the epidermal tissue into the water on the slide
3. add a drop of iodine solution to stain it (stains are used to highlight objects in a cell by adding colour)
4. place a cover slip on top, which is plastic or glass, and Try not to get any air bubbles
