Enzyme purification is carried out by contacting an impure liquid enzyme preparation containing enzyme and soluble impurities with an ion exchange material in a column to adsorb both the enzyme and impurities by the ion exchange material, adding an additional amount of the impure liquid enzyme preparation...http://www.google.com/patents/US4347322?utm_source=gb-gplus-sharePatent US4347322 - Chromatographic process for enzyme purification
