EMD MILLIPORE UFC501096 Amicon Ultra Centrifugal Filter Unit with Ultracel-10 Membrane, Clear, 0.5 mL Volume, 1 sq. cm. Filtration Area, 10.8 mm Diameter x 49.9 mm L: Amazon.com: Industrial & Scientific
Amicon Ultra-0.5 Centrifugal Filter Unit Ultracel-30 regenerated cellulose membrane, 0.5 mL sample volume | Sigma-Aldrich
Millipore UFC803096 Regenerated Cellulose Amicon Ultra Centrifugal Filter Unit with PLTK Ultracel-30 Membrane, 4mL Capacity, 30kDa NMWL, 17.3mm Diameter x 124mm Length, 3 sq cm Membrane (Pack of 96): Science Lab Centrifugal