Required practical 2 - Calculating Mitotic index using Plant cells

Outline the method to find the mitotic index of plant cells:

1. Warm HCl to 60 degrees in a water bath

2. Cut the root tip using a scalpel, and add HCl and leave for 5 minutes.

3. Remove HCl and wash with distilled water

4. Cut the tip of the root tip sample and place on a slide

5. Add a few drops of stain to make the chromosomes visible

6. Using a mounting needle use a coverslip to then crush the coverslip so the cells are one cell thick

7. View the mircropscope and count the total number of cells in the sample, and count the number of cells undergoing mitosis

8. Then calculate the mitotic index = Number of cells undergoing mitosis / Total number of cells in view

Why is the meristem of the plant cell used?

• This is where most cells undergoing mitosis takes place

Why is HCl added?

• This stops the cells undegoing mitosis so can calculate the mitotic index at a given point

Why is a stain used?

• A stain is used to view the chromosomes