Diafiltration is a unit operation that incorporates ultrafiltration membranes to remove salts or other microsolutes from a solution. Small molecules are separated from a solution while retaining larger molecules in the retentate. Microsolutes are generally so easily washed through the membrane that for a fully permeated species about 3 volumes of diafiltration water will eliminate 95% of the microsolute. Novasep sells tangential flow membranes, cassettes and systems for your biopharmaceutical diafiltration challenges.