Tisch Scientific PTFE Syringe Filter, 0.45 µm, 25 mm, Luer-Lok/Luer Slip, Non-Sterile, 100 Pack, SF14469 . Tisch PTFE Syringe filters are very versatile, proving to be effective for applications such as alkali filtration, strong acid solvent filtration, and organic solvent with strong chemical causticity filtration.