To study mitosis by preparing a temporary mount of an onion root tip.
Necessary Materials & Apparatus
- Watch glass
- Glass slide
- Filter paper
- N/10 Hydrochloric acid
- Acetocarmine Stain
- Compound microscope
- Place the onion on a tile
- Using the blade, remove the dry roots
- Regrow the root tips by placing the bulbs in a water-filled beaker
- After 3 to 6 days, new roots may emerge
- Slide 2 to 3 cm off freshly grown roots and place them on a watch glass
- Use a forceps to transfer the freshly cut tips to a test tube containing Aceto-alcohol (1:3 = anhydrous acetic acid: ethanol)
- Submerge the root tips in the solution for 24 hours
- Use the forceps to take out a single root and place it on a glass slide.
- Put a single drop of N/10 HCl on the root tip
- Then, put 2-3 drops of acetocarmine stain
- Use a burner to warm it, and ensure that the stain does not dry up.
- Use a filter paper to blot out the excess stain, if any
- Cut the significantly stained portion of the root using a blade and place it on a slide. Discard the rest of the root
- Put a drop of water on the root tip
- Place a coverslip using a needle
- Tap the coverslip such that the meristematic tissue of the root tip is compressed and spread out as a thin layer.
- The preparation is ready for studying mitosis.
Use the compound microscope to study the various phases of mitosis.