Millipore Millex® GP sterile syringe filters feature Millipore Express® polyethersulfone membrane (PES), which provides a unique combination of speed and six times less protein binding than competitive PES membranes. Millex® GP syringe filters are recommended for sterile filtering protein solutions, tissue culture media, buffers and additives. The larger filter surface area of 33mm syringe filters increases flow rate and throughput. It also makes it easier to filter solutions because it reduces the pressure required to empty the syringe. Millex® 33mm syringe filters have a maximum housing pressure of 10.5 bar (150 psig), which means you can filter solutions faster than before. Millex® syringe filters are manufactured in a controlled environment for consistently reliable performance using an automated process. Human hands never touch the filter during assembly. A Certificate of Quality included in each box describes Millipore's quality standards in detail. Pre-sterilized by ethylene dioxide method.