Ion exchange process for separating proteins

Claim 1

A PROCESS OF SEPARATING A PROTEIN FROM OTHER PROTEINS IN AN AQUEOUS SOLUTION CONTAINING A PLURALITY OF PROTEINS AS SOLUTES AND ALSO HAVING A SALT CONTENT PRESENT AS CATIONS AND ANIONS IN A CONCENTRATION RENDERING SAID FIRST-MENTIONED PROTEIN SOLUBLE IN SAID SOLUTION AND IN THE ABSENCE OF WHICH CATIONS AND ANIONS SAID PROTEIN IS INSOLUBLE IN SAID SOLUTION, ANOTHER PROTEIN SOLUTE OF SAID SOLUTION BEING SLUBLE THEREIN IN THE ABSENCE OF SAID CATIONS AND ANIONS IN SAID CONCENTRATION, COMPRISING THE STEPS OF PROVIDING A MIXTURE OF CATION-EXCHANGE AND ANION-EXCHANGE RESINS CONDITIONED TO BE IN EQUILIBRIUM WITH AN ION CONCENTRATION AT WHICH SAID SOLUTION-CONTAINED CATIONS AND ANIONS ARE REMOVED FROM SAID SOLUTION BEING TREATED SO THAT SAID RESINS WILL SORB FROM SOLUTION SAID CORRESPONDING IONS, PASSING SAID AQUEOUS SOLUTION OF SAID PROTEINS AND SALT SOLUTE IN CONTACT WITH SAID CATION-EXCHANGE RESIN AND SAID ANION-EXCHANGE RESIN ADJUSTING THE PH OF THE SOLUTION TO BE IN THE RANGE PH1 TO LESS THAN PH6 BY ION-EXCHANGE BETWEEN SAID SOLUTION AND SAID RESINS, REMOVING FROM SAID SOLUTION SAID SOLUBILIZING CATIONS BY ION EXCHANGE WITH SAID CATION-EXCHANGE RESIN TO REDUCE SAID SOLUBILIZING CATIONS AND REMOVING FROM SAID SOLUTION SAID SOLUBILIZING ANIONS BY ION EXCHANGE WITH SAID ANIONEXCHANGE TO RESIN TO REDUCE SAID SOLUBILIZING ANIONS, AND THEREBY PRECIPITATING SAID FIRST-MENTIONED PROTEIN FROM SAID SOLUTION OF SAID PROTEINS, AND SEPARATING SAID PRECIPITATE FROM SAID SOLUTION.