Millipore® Ultrafiltration Disk Membranes, model PLHK04310 is manufactured by Merck KGaA. This product is made from PLHK cellulosic (regenerated cellulose) material. It has a well-defined pellicle structure that retains molecules and particles larger than nominal molecular weight cut off (MWCO), while allowing lower molecular-weight solvent and solutes to pass through. Dramatic concentration of macromolecules can be achieved with UF membranes.