Steriflip filter device incorporates the proprietary Express PLUS low protein binding PES (polyethersulfone) membrane. The sterile device has 7 cm² of membrane for sterilizing up to 50 ml of tissue culture media additives, microbiological media, or biological solutions. The filter unit is attached to a centrifuge tube containing a sample and vacuum is applied. Sample is sterile filtered through the device into a sterile 50 ml collection tube. This eliminates sample transfers between containers, minimizing the chance of contamination. The device can be used with standard 50 ml centrifuge tubes having a double-start thread design. The filter device is also available with other membrane materials.