Alpha Laboratories Polycarbonate Membrane Filters are manufactured from high-quality polycarbonate film using track-etch technology. They have a smooth, flat surface that exhibits an even capillary pore structure and narrow pore size distribution, allowing for high particulate retention and visibility on the membrane surface. The high flow rates and excellent thermal and chemical resistance of Track-etched Polycarbonate Membrane Filters, make them a suitable choice for precise detection and fractionation of particles in many corrosive fluids. They demonstrate very low levels of extractables making them suitable for a wide range of other applications including biological cell analysis, water microbiology, environmental analysis, fluid clarification, cytology, parasitology, bioassays and epifluorescence microscopy. These Polycarbonate Membrane Filters are supplied as 47mm diameter discs with a pore size of 0.45µm and a membrane thickness of 0.25mm. The water flow rate is 33ml/min/cm² and the air flow rate is 7.5L/min/cm². They are equivalent to Whatman™ Nucleopore™ Polycarbonate Track-Etched Membrane Filters. Alpha Laboratories Polycarbonate Membrane Filters are plain, white and supplied non-sterile in a box of 100 discs.