Abstract: Disclosed are resins, resin-protein/peptide complexes and methods for purifying proteins and peptides using said resins. The resins described herein are useful for the binding of a selected protein or peptide, particularly from an aqueous medium such as a fermentation broth, by hydrophobic interactions between the resin and the selected protein or peptide. The resin is characterized by the fact that it contains ionizable ligands and/or functionalities which are uncharged at the pH of binding the target protein or peptide, thereby facilitating hydrophobic interactions, and charged at the pH of desorption, thereby disrupting the established hydrophobic interaction between the resin and the target protein or peptide. More particularly, the present invention is directed to the use of the described resins in the purification of recombinant enzyme products such as proteases, for example, chymosin or subtilisin.

Abstract: Disclosed are rationally designed mixed mode resins which are useful in recovering a target compound from an aqueous solution and methods for use of such resins. The resins described herein have a hydrophobic character at the pH of binding of the target compound and a hydrophilic and/or electrostatic character at the pH of desorption of the target compound from the resin and are specifically designed to bind the target compound from an aqueous solution at both a low and high ionic strength.

Abstract: Disclosed are rationally designed mixed mode resins which are useful in recovering a target compound from an aqueous solution and methods for use of such resins. The resins described herein have a hydrophobic character at the pH of binding of the target compound and a hydrophilic and/or electrostatic character at the pH of desorption of the target compound from the resin and are specifically designed to bind the target compound from an aqueous solution at both a low and high ionic strength.

Abstract: There is described a mobile phase for use in the purification of proteins using reversed phase HPLC on a preparative scale. The mobile phase is an aqueous solution containing 0.005 to 1M of a physiologicially acceptable acid of the general formula YCOOH where Y is a polar electron withdrawing group capable of hydrogen bonding silanol groups. The solution also contains up to 95% by volume of a physilogically acceptable organic solvent. A preparative method of purifying proteins such as HSA or BSA and recombinant deoxyribonucleic proteins using reversed phased PHLC is also described.

Abstract: A process is described for removing low density and very low density lipoproteins from blood plasma or serum and recovering the plasma or serum in a physiologically acceptable form. The method involves in a preferred embodiment passing plasma or serum through a cationic ion exchanger equilibrated with a physiologically acceptable saline solution. The ion exchanger is a water insoluble hydrophilic, water swellable cross-linked regenerated or microgranular cellulose matrix substituted with hydroxy C.sub.2 -C.sub.4 alkyl group. The ion exchanger capacity is provided by sulphate groups substituted with from 2 to 6 meq/g. The take up of low density lipoproteins is enhanced by recycling the plasma through the column.