1. Identification of Biological
Molecules
ALBIO9700/2006JK

2. Testing for the presence of sugars
(Benedict’s test)
ALBIO9700/2006JK

3. Testing for the presence of sugars
(Benedict’s test)
ALBIO9700/2006JK

4. Testing for the presence of sugars
ALBIO9700/2006JK

5. Testing for the presence of starch
(iodine solution)
ALBIO9700/2006JK

6. Testing for the presence of lipids
(emulsion test)
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7. Sudan III
• Tissue that has been ground up is
transferred to a test tube containing water
and boiled
• Oil droplets will escape the tissue and rise
to the surface
• Add 2 cm3 Sudan III, shake and allow the
oil to settle
• Oil will be stained red
ALBIO9700/2006JK

8. Testing for presence of protein
ALBIO9700/2006JK

9. Biuret test
• Suitable for soluble proteins
• Add equal amount of 1% potassium hydroxide
(KOH) to solution
• Add a few drops of 1% copper (II) sulphate
(CuSO4) solution down the side of test tube
• A blue ring at the surface of the solution
indicates protein
• On shaking, the blue ring disappears and the
solution turns purple
ALBIO9700/2006JK

10. Millon’s test
• For insoluble proteins
• 6 drops of Millon’s reagent to a small
amount (3 cm3) of solution or suspension
of protein and boil for 5 minutes
• After cooling, add a few drops of 1%
sodium nitrite
• If protein is present, a brick-red
precipitate appears on the surface
ALBIO9700/2006JK