Protein chromatography in neat organic solvents

Pure formamide and ethylene glycol are used instead of water as processing media for protein chromatography. A number of common proteins are freely soluble in these solvents and most do not undergo irrersible inactivation in them. Batch adsorption studies reveal that proteins readily adsorbed to various ion-exchangers in formamide and ethyline glycol and subsequently can be completely desorbed by adding inorganic salts (LiCl and NH(4)NO(3)) to the solvents. The idea of protein separations in formamide and ethylene glycol is illustrated by column chromatography and preparative separation of mixtures of (i) oxidized A and B chains of insulin and (ii) lysozyme and ribonuclease on the anion-exchanger triethylaminoethycellulose and the cation-exchanger phosphocellulose, respectively.