The phenyl membrane adsorber follows the same rules known from the conventional hydrophobic interaction chromatography. Due to the large pore size, Membrane Adsorbers show excellent flow properties. There is almost no diffusion limitation of mass transport compared with conventional bead chromatography. On average 50% of a protein or peptide surface is accessible for hydrophobic interaction. Buffers with high concentrations of salt promote the adsorption of proteins on the hydrophobic membrane matrix. Proteins are eluted by decreasing the salt concentration in the elution buffer.