Eppendorf centrifuge filters are available in three sizes for volumes up to 0.5mL, 4.0mL, and 15mL. The removable, invertible filters have been designed to fit completely inside standard 2mL, 13mL, or 50mL centrifuge tubes.
Six membrane pore sizes are available with molecular weight cut-offs of 4kD, 10kD, 30kD, and 100kD, and pore sizes of 0.22µm and 0.45µm.
The filter design allows for an almost complete recovery of retention volume and provides efficient concentration up to 300x. The entire filter insert is sealed inside the tube, which can minimize risk of spillage, contamination, and potentially harmful aerosols. Brinkmann Instruments