The separation of proteins and peptides based upon hydrophobic characteristics is a powerful chromatographic technique. However, some proteins denature at elevated organic solvent concentrations making reversed-phase chromatography (RPC) difficult. Waters BioSuite™ Phenyl HIC columns provide a viable separation alternative to RPC. HIC is characterized by the adsorption of compounds to a weakly hydrophobic surface at high salt concentrations, followed by elution with a decreasing salt gradient. HIC combines the non-denaturing characteristics of salt precipitation with the precision of HPLC to yield excellent separation of biologically active material. Waters BioSuite™ Phenyl, 1000, 10 µm HIC column media consists of a phenyl group bonded to a methacrylic ester-based polymeric resin. The large 1000 angstrom pore size accommodates proteins up to 5,000,000 Daltons. A 21.5 mm x 150 mm column is also available for "labscale" isolations.