These sterile syringes filters with Supor PES (polyethersulfone) membranes are ideal for cell culture, biological research, and the filtration of other aqueous solutions. The 25 and 32 mm varieties have a color-coded modified acrylic housing, and 13 mm varieties have a polypropylene housing.Syringe filters are attached to the end of a syringe to remove particles from a sample prior to analysis