The Polyethersulfone (PES) membrane by Whatman™ is hydrophilic low protein binding and stable in alkaline pH. This polyethersulfone membrane filter features a 0.8µm pore size and is recommended for aqueous filtration applications and biological sample filtration. The PES membrane also has a smooth surface that allows for easy enumeration of artifacts. Polyethersulfone Media, Diameter: 47mm. Pore Size: 0.8µm. 100/Pack. Whatman™ #: 111164.