Whatman GD/X Syringe Filters are high-viscosity filters that incorporate a prefilter to enable filtration of viscous, dense or otherwise hard-to-filter material with high solids content as in environmental and food analysis samples. This product is recyclable. Learn how you can recycle it.Non sterile Whatman GD/X Syringe Filters combine a polypropylene housing, high-efficiency Whatman GMF 150 and GF/F pre-filter media, and one of the following membrane materials: Polyethersulfone (PES) for serum, plasma and tissue culture Polyvinylidene difluoride (PVDF) for HPLC Cellulose acetate for biological solutions Borosilicate glass microfiber High viscosity filter enables filtration of “difficult-to-filter” samples The prefilter contains a high-efficiency borosilicate glass filtration stack that will retain fine particles down to 0.7 μm, allowing difficult sample filtration with less hand force. It reduces the need for multiple syringe filters by processing three to seven times more sample volume than syringe filters without prefilters. The filters can be autoclaved.