The SelRO nanofiltration membranes provide outstanding chemical and thermal stability to satisfy the demanding requirements of pharmaceutical processes involving high and low pH, high temperature and organic solvents media. The SelRO acid/base stable membranes can be operated within the pH range of 0-14. The ROMIPRO hollow fiber ultrafiltration cartridges provide cost-effective purification and concentration for separation of enzymes, proteins and polypeptides. They are available in a number of sizes for pharmaceutical laboratory process filtration, pilot plant process filtration and product manufacturing filtration.