Thin, precut membrane rounds for high-throughput, fast filtration of liquid and gas samples. Gridded and non-gridded discs. Various materials including mixed cellulose ester, polycarbonate, PTFE, nylon, and PVDF. For air monitoring/analytical research.

Sizes

Filter membranes are made in a range of diameters, typically designed to fit a specific holder or manifold.

Materials

Filter membrane can be made from cellulose, mixed cellulose esters (MCE), polyvinylidene fluoride (PVDF), polyethersulfone (PES), polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), nylon, polycarbonate (PC), polyester, polyethylene terephthalate (PET), and polypropylene (PP). Other membrane materials include aluminum oxide, gelatin, porcelain, and glass.

Pore Size

The size of membrane pores determines which particles will be retained by the filter. A pore size of 0.2 µm is small enough to remove microbes from solutions; a 0.45 µm ore size can remove larger particulates.

Color and Grids

White membrane filters may be plain or marked with square grids (outlined in black) that can help with enumerating particles. Gridded or plain black membrane filters may be helpful when filtering light-colored particulates.

Sterility

Filter membranes may be pre-sterilized or may be sterilized using ethylene oxide, gamma irradiation, or autoclaves. The need for sterility is determined by the application, which are many and varied:

• Light microscopy samples
• Cytology sample preparation
• Electron microscopy samples
• Air quality and other environmental monitoring
• Water analysis and water quality testing
• Microbiology colony counting and quality control
• Chemotaxis
• Sterile preparation of buffers, tissue culture media, microbiological media, and other biological fluids