Aqueous (normal phase) chromatography is used extensively to purify proteins and peptides from mixtures of natural materials.  We routinely use aqueous phase chromatography to analyze and isolate proteins for subsequent amino acid sequence analysis, compositional analysis or downstream Proteomics analysis.  The PCL has two GE Healthcare/Pharmacia Acta systems and a small library of columns that includes hydrophobic interaction, ion exchange, metal chelation and affinity matrices.  We recently introduced Immuno-Depletion chromatography to our menu (for Proteomics studies of physiological fluids and serum-contaminated samples).