Hello! I am confused about the protein interactions that occur when either salt concentration is increased or an organic solvent is introduced. When salting out, wiki says: "Addition of a neutral salt, such as ammonium sulfate, compresses the solvation layer and increases protein-protein interactions. As the salt concentration of a solution is increased, more of the bulk water becomes associated with the ions. As a result, less water is available to partake in the solvation layer around the protein, which exposes hydrophobic patches on the protein surface. Proteins may then exhibit hydrophobic interactions, aggregate and precipitate from solution." And for organic solvents: "The solvation layer around the protein will decrease as the organic solvent progressively displaces water from the protein surface and binds it in hydration layers around the organic solvent molecules. With smaller hydration layers, the proteins can aggregate by attractive electrostatic and dipole forces." Both seem to be saying that the hydration laayer is removed, and yet this leads to different interactions... I was reading from this source: http://teachline.ls.huji.ac.il/72682/Booklets/AMERSHAM_HIC_RPC.pdf about reverse phase chromatography, and it states that increasing organic solvent concentrations elutes the protein. From my understanding RPC works by incraesing the hydrophobic character of the eluent to compete with the stationary phase. In which case, hydrophobic interactions are increased, not electrostatic ones, as wiki says. Is it just me? Thanks in advance.