Methods of Protein Precipitation

Protein Precipitation Methods
🧪 Acid Precipitation: 5 to 10 drops of acid are added to the albumin solution, leading to protein denaturation evidenced by cloudy material formation.
⚖️ Heavy Metal Precipitation: Lead acetate solution is added to 2 ml of albumin, resulting in protein precipitation as a complex with the heavy metal ion.
🧪 Picric Acid Precipitation: Adding 1 ml of picric acid solution to 2 ml of albumin solution causes protein denaturation, visible as cloudy material.
💧 Organic Solvent Precipitation (Ethanol/Acetone): Adding 2 ml of ethanol or acetone to 2 ml of albumin solution decreases protein solubility by displacing water molecules associated with the protein.

Mechanism of Organic Solvent Action
🚫 The addition of alcohol (ethanol or acetone) reduces the available water in the protein solution, directly causing a decrease in protein solubility.

Key Points & Insights
➡️ Protein precipitation techniques include using acids, heavy metals (like lead acetate), picric acid, and organic solvents (ethanol and acetone).
➡️ Denaturation by acid or picric acid is visually confirmed by the formation of cloudy material.
➡️ Organic solvents like ethanol and acetone precipitate proteins by reducing the effective water concentration needed for protein hydration and solubility.

📸 Video summarized with SummaryTube.com on Nov 24, 2025, 05:23 UTC