Oct 29, 2021 · Whatman Puradisc 13 mm H-PTFE Syringe Filters 0.2 µm, Hydrophilic, 100 Pack, 6772-1302 . Whatman’s Puradisc syringe filters are made to serve a wide variety of applications including capillary electrophoresis, biological preparations, protein filtration, and UV spectroscopy sample preparation.