New 33 mm Sample Preparation Millex syringe filters with low-protein-binding Durapore membrane are optimized for preparing 10 to 100 ml of protein-containing aqueous and mild organic solutions prior to instrument analysis. The filters have almost 20% greater surface area than standard 25 mm filter units to deliver faster flow rates and higher throughput. Increased surface area reduces the pressure required to easily pass a solution through the syringe. Operating pressure of 100 psig (10 bar) allows solutions to be filtered rapidly. The units are available in 0.20 μm and 0.45 μm pore sizes, which remove the fine particles that can prematurely plug chromatography columns.