Filters with PTFE (polytetrafluoroethylene) membrane that satisfy requirements of life science applications for sterilization of solutions or clarification of biological fluids. Include a polypropylene microfiber pre-filter layer to improve filtration of particulate-laden fluids that are difficult to filter with single layer syringe filters. Individually packaged in peelable blister with filter diameter, membrane type, and membrane porosity clearly marked on the package. Sterilized by Gamma Irradiation to SAL 10 -6. Feature high flow rates and low absorption membranes for minimal sample loss.