How is protein purification achieved using HPLC techniques?

Protein purification using HPLC techniques involves separating proteins based on their size, charge, and hydrophobicity. The process involves passing a protein mixture through a column filled with a stationary phase that interacts with the proteins differently, allowing for their separation. The proteins are then eluted from the column using a solvent gradient, with each protein eluting at a different time based on its unique characteristics. This results in the isolation of pure proteins for further analysis or use.