Everything Life Sciences Grade 10

minerals. The best

animal protein

sources are fish and

poultry.

1. bunsen burner and a beaker containing water


2. orwater bath with hot water (50◦C)


3. Dropper or plastic pipette


4. Test tubes:
   
   
   • two with albumin solution (positive control)
   
   
   • two with sugar water (negative control)
   
   
   • test tubes with samples to be tested for the presence of protein
   
   
   • test tube with Millon’s Reagent
   
   
   • test tube with solution for Biuret test
   
   
   
   

(NOTE:The Millon’s Reagent and Biuret’s solution in this experiment should be prepared
for you by your teacher).

Method:

Test for protein using Millon’s reagent

WARNING! Millon’s reagent is highly toxic! Avoid breathing in its fumes.

1. Using the dropper or pipette, add a few drops of Millon’s Reagent to the test-tube
   containing albumin.


2. Using the dropper or pipette, add a few drops of Millon’s Reagent to the test-tube
   containing sugar water.


3. Using the dropper or pipette, add a few drops of Millon’s Reagent to the test-tube
   containing samples of your food to be tested.


4. Heat the mixtures in boiling water for 5 minutes.


5. Observe any colour changes.

Test for protein using the Biuret test

1. Using the dropper or pipette, add a few drops of the Biuret solution to the test-tube
   containing albumin.


2. Using the dropper or pipette, add a few drops of the Biuret solution to the test-tube
   containing sugar water.


3. Using the dropper or pipette, add a few drops of the Biuret solution to the test-tube
   containing samples of your food to be tested.


4. Observe any colour changes.

Chapter 2. The chemistry of life 41