A process for the isolation and/or purification of a desired component, particularly 3′sialyl lactose, from whey, particularly cheese whey, comprising the steps of: optionally subjecting the whey to ultrafiltration to provide a protein concentrate and a whey permeate contacting the whey or whey permeate with at least one series of ion exchange resins, said series comprising a first weak acid cation resin, a first weak base anion resin, a second strong acid cation resin, a second weak base anion resin to demineralize the whey permeate contacting this demineralized permeate with two final ion exchange resins comprising a strong acid cation resin and a final weak base anion resin, wherein the desired component, such as 3′ sialyl lactose, is taken up on the final anion resin and eluting the desired component from the final anion resin.
