Forensic Chemistry > 3. Because proteins are a major structural and metabolic component of all living organisms, the analysis of protein samples can be useful in forensic chemistry > A Distinguishing Test For Proteins >
Perform a first-hand investigation and gather first-hand information about a distinguishing test for proteins
- Known test for the identification of peptides and proteins
- Involves the use of Biuret reagent which is made up of Sodium hydroxide and Copper (II) sulfate
Experiment: Protein Identification using Biuret Test
Reagent: Biuret reagent (1% CuSO4 and 10% NaOH)
- Place two test tubes in a test tube rack. Transfer 2 mL water in the first and 2 – mL gelatin solution in the second tube.
- Add drops of Biuret reagent in each tube.
- Compare test tube 1 (Control) with the colour of the gelatine solution in test tube 2. Record for observations
- The gelatine solution turned changes color to purple, indicating the presence of proteins or peptides
- The change in colour is due to a coordination complex between the Cu2+ ions and the C—N and C=O atoms on the peptide group