Biuret Protein Assay Overview

Objective

• Students will be able to test protein presence in substances.
• Students will reflect on two case studies related to collagen defect.

Principle

• Biuret protein assays are based on the principle that copper ions in the reagent react with peptide bonds in proteins.
• The reaction forms a complex that absorbs light at a specific wavelength.
• The intensity of the purple color is directly proportional to the protein concentration in the sample.
• The amount of protein can be quantified by measuring the absorbance.

Negative Biuret Test

• Blue color indicates proteins are absent.

Positive Biuret Test

• Purple color indicates proteins are present.

Biuret Protein Assay

• A simple, sensitive, and reproducible method for determining protein concentration in a sample.
• Widely used in biochemical and biological research
• Can be performed on a wide range of protein samples, including purified proteins, cell lysates, and biological samples.
• Can be used to perform various biochemical and biological studies (enzyme kinetics, protein-protein interactions, and protein expression studies).

Materials

• 6 Test Tubes
• 1 Test Tube Rack
• 2 Test Tube Holders
• 2 250mL Beakers
• 1 10 mL Graduated Pipet
• 1 Pipet Bulb
• 1 Dropper
• 1 Hotplate
• 10% NaOH Solution
• 5% Copper Sulfate Sol'n