In column chromatography, how are proteins sorted?

In column chromatography, proteins are sorted based on their hydrophilic or hydrophobic properties. This technique often employs a stationary phase that has different affinities for various proteins depending on their chemical characteristics.

When a mixture of proteins is passed through the column, those that are hydrophobic tend to interact more strongly with the hydrophobic stationary phase and will thus elute more slowly compared to hydrophilic proteins, which are more soluble in the mobile phase and pass through the column more quickly. This differential interaction allows for the separation of proteins as they travel through the column at different rates, ultimately leading to their collection in distinct fractions.

This process is crucial in protein purification, enabling researchers to isolate specific proteins from complex mixtures based on their unique hydrophobic or hydrophilic traits. Other sorting methods, such as those based on size or charge, involve different principles and techniques (such as size-exclusion chromatography or ion-exchange chromatography), which do not apply in this context.