Membran Solutions PES filter membrane is produced by a unique preparation process: dry/wet/mixed method, with high flow rate/high throughput/autoclave resistance/no adsorption of proteins and extracts/no pollution to the sample. Aperture 0.02 to 0.05 mu mu 0.03 mu m/m/m / 0.1 to 0.45 mu mu 0.22 mu m/m/m / 0.65 mu m / 0.8 mu mu m 1.0 mu m/m / 1.2/5.0. The super asymmetric pore structure of the membrane has a higher porosity and a higher water flux than other membranes (under the same pore size). PES membranes' low protein adsorption properties make them very suitable for preparing biological samples. Membran Solutions PES filter membrane is produced by a unique preparation process: dry/wet/mixed method, with high flow rate/high throughput/autoclave resistance/no adsorption of proteins and extracts/no pollution to the sample. Aperture 0.02 to 0.05 mu mu 0.03 mu m/m/m / 0.1 to 0.45 mu mu 0.22 mu m/m/m / 0.65 mu m / 0.8 mu mu m 1.0 mu m/m / 1.2/5.0. The super asymmetric pore structure of the membrane has a higher porosity and a higher water flux than other membranes (under the same pore size). PES membranes' low protein adsorption properties make them very suitable for preparing biological samples.