Researchers will experience fast filtration flow rates with NALGENEâ MF75® Filter Units and Bottle Top Filters, which incorporate the new sterilization-grade Pall Suporâ machV membrane. The membranes are composed of polyethersulfone (PES), the same material used for processing biological and pharmaceutical samples for drug discovery and basic research. The advanced, three-dimensional, V-shaped structure of Supor® machV membranes accelerates flow rates up to 50 percent, while exhibiting low protein binding of cell culture media and other solutions. These filters allow rapid sterile filtration of even the most difficult to filter fluids such as serum. The 0.2 mm Supor® machV membranes are available in 150 mL, 250 mL, 500 mL, and 1 L sizes.