What occurs when lysate is applied to the column in a high salt buffer?

When lysate is applied to the column in a high salt buffer, hydrophobic proteins tend to stick to the beads. This is due to the principle of hydrophobic interaction chromatography, where the beads in the column are often coated with hydrophobic materials. In a high salt environment, proteins are encouraged to expose their hydrophobic regions because the salt reduces the solubility of these hydrophobic portions in the aqueous buffer. This promotes interaction between the hydrophobic regions of the proteins and the hydrophobic beads, resulting in the binding of hydrophobic proteins to the column while more polar or hydrophilic proteins will typically remain in the mobile phase and wash through the column.

In summary, the high salt buffer enhances the attraction between hydrophobic proteins and the column's beads, leading to effective trapping of these proteins and allowing for subsequent purification steps. This answer aligns with the principles of protein purification techniques, providing a clear rationale for why hydrophobic proteins are retained in the column under these conditions.