Starch Agar Experiment - LC Biology

List the materials needed

1. 4 soaked broad bean seeds

2. 2 sterile starch/skimmed milk agar plates

3. Iodine/biuret reagent

4. Disinfectant

5. Sterilised water

6. Mild disinfectant

7. 2 beakers

8. Boiling water bath

9. Thermometer

10. Incubator - 18 to 20 degrees Celsius

11. Forceps

12. Backed blade and chopping board

13. Labels

14. Bunsen burner

What should you label the sterile plates?

Raw and Boiled

How do you kill 2 of the seeds

Boil them for 5 minutes

What is the purpose of the boiled seeds?

A control

Why do we split each seed in half?

To separate the cotyledons

How do you sterilise the seeds?

Soak them in mild disinfectant for 10 minutes

What do you do after sterilising the seeds?

Rinse them twice using sterilised water

How do you sterilise forceps?

By flaming them in a Bunsen burner

How do you place the seeds on the plates?

With minimal opening use the forceps to place the seed halves face down on the agar in the appropriate plates

How should you incubate the plates?

Upright, at 18-20 degrees Celsius, for 48 hours

What should you do after removing the seeds from the plates if you used starch agar plates (3 steps)

1. Flood plates with iodine and leave for 2 minutes

2. Pour off iodine

3. Observe pattern of starch digestion by holding plate up to the light

What should you do after removing the seeds from the plates if you used skimmed milk plates (3 steps)

1. Flood plates with biuret reagent and leave for 2 minutes

2. Pour off biuret reagent

3. Observe pattern of protein digestion by holding plate up to the light