How onion peel and cheek cell are stained?
Answers
Cheek cell using Methylene blue
Onion peel is stained with "safranin stain" and cheek cells are stained with "methylene blue stain".
The epidermal peel of onion is removed, dipped in safranin solution and mounted in glycerine on a glass slide. Safranin is a red coloured stain. The peel is made by “rectangular cells”. Each cell has a “distinct cell wall”, lightly stained cytoplasm, a central vacuole and a deeply stained nucleus towards the cell periphery.
A smear of cheek cells, taken with a cotton swab is placed on a ‘glass slide’, a drop of ‘methylene blue’ solution is added and excess stain is removed. Methylene blue stains the ‘negatively charged molecules’ in a cell. Cheek cells appear as large polygonal, with cytoplasm, no cell wall, a large vacuole and a nucleus.