CBSE Class 10 Science 2019 · Paper 31/5/1 · Question 26

Safranin - when: after the thin peel is removed from the leaf and before it is mounted; the peel is kept in a few drops of safranin for 1 to 2 minutes and then rinsed in water. Why: it stains the cells, so the epidermal cells, the guard cells and the stomata can be seen clearly under the microscope. Glycerine - when: while mounting; a drop is put on the stained peel on the slide just before the cover slip is placed. Why: it prevents the peel from drying up during observation.