Onions in focus

Aim: To investigate onion cells and to practise using the microscope. Materials & Equipment: - Glass slide - Cover slip - Onion layer (1 cell thick) - Iodine stain - Microscope - Water & syringe Method: 1) If necessary, carefully clean the cover slip and glass slide (always hold the glass by the edges) 2) From a piece of onion, carefully peel a layer of its skin (one cell thick) and put it on the glass …

…that no air gets trapped underneath. Trapped air makes it harder to see. We stained the onion skin with "iodine stain" to make the cells stand out. We should avoid getting air bubbles trapped under the cover slip to have a clear view of the cells. Conclusion: In this experiment I have learned how to better use different parts of the microscope. I also discovered the different shapes of the onion cell and their colours.