Question

In an experiment to prepare a temporary mount of leaf peel, staining of the peel is done before putting a drop of glycerine. Explain why?

Answer 1

Temporary mount of a leaf peel is used to observe stomata. Stomata are small openings found widely scattered on the epidermis of leaves and young stems.

Glycerine is a dehydrating agent. Once glycerine is added it forms a protective layer that keeps it moistened. It avoids the drying of the specimen. If staining is done after adding glycerine then the specimen will not be stained properly because the stain will be washed off with glycerine.

So staining is done before adding glycerine so that the specimen can absorb the stain and if there is any excess stain present, it is removed by adding glycerine.