Microscopy of red bell pepper skin: the importance of having a thin specimen

This resource uses sections of red bell pepper wall to teach students about the importance of having a thin specimen when using a compound light microscope. Using the red bell pepper provides students with an interesting question to explore and a simple specimen to prepare enabling all students to develop their basic practical microscopy skills and build their understanding of the principles of microscopy.

Students can be given a section of the wall of a red bell pepper and asked to explore what makes its skin red. If they place the whole section of the wall under the microscope they just see a mass of redness but no clear cellular contents. However, if they peel off the outer ‘skin’ and view that under the microscope they can see the chromoplasts which give the skin its colour.