Vivaspin 20 handles up to 20 ml in swing bucket centrifuges and 14 ml in fixed angle rotors accepting 50 ml centrifuge tubes. Broad range of process alternatives for the filtration and concentration of biological samples Disposable ultrafiltration devices concentrate and purify biological samples to concentrations over 100x in a single spin! Concentrators feature twin vertical membranes—increased surface area provides faster filtration Polyethersulfone membrane is excellent for most solutions when recovery is most important.