Applications:

1. Protein Purification and Separation: In biochemical and pharmaceutical research laboratories, the isoelectric point is used to separate proteins and peptides via isoelectric focusing (IEF) or ion-exchange chromatography. Knowing the pI helps in choosing the correct pH for optimal protein isolation.
2. Drug Formulation and Stability: In biopharmaceutical industries, determining the pI of peptide-based drugs is crucial for optimizing solubility and stability. Peptides and protein-based drugs are often stored at pH values away from their pI to prevent aggregation or precipitation.
3. Food Science and Dairy Industry: The pI of milk proteins, such as casein, determines milk curdling during cheese production. Adjusting pH close to the pI allows for precipitation of proteins, which is a critical step in cheese and yogurt manufacturing.
4. Forensic and Clinical Diagnostics: In electrophoresis-based diagnostics, such as serum protein electrophoresis, knowing the pI helps detect abnormalities in proteins linked to diseases like multiple myeloma or inflammatory conditions.
5. Understanding Disease Mechanisms: Many genetic disorders affect protein charge and stability. For example, sickle cell anaemia alters haemoglobin’s isoelectric point, affecting its behaviour in blood. Studying pI variations helps understand and diagnose hereditary diseases.