Ultrafiltration unit with a MWCO of 10,000 Dalton and a unique twin membrane (polyethersulfone), suitable for starting volumes up to 20 ml for sample concentration with high process flexibility: centrifugation or centrifugation of pressurised units, as well as pressure filtration in stationary benchtop mode.

Vivaspin® 20 centrifugal concentrators have been developed to offer increased volume flexibility and performance. Vivaspin® 20 handles up to 20 ml in swing bucket rotors and 14 ml in fixed angle rotors accepting 50 ml centrifuge tubes. Vivaspin® 20 features twin vertical membranes for unparalleled filtration speed and >100-fold concentration. Volume graduation allows to monitor the concentration process and the modified dead stop pocket simplifies pipetting of the final concentrate. For higher process flexibility, Vivaspin® 20 is available with unique accessories and operating methods. For one-step desalting following concentration, a diafiltration cup filled with buffer is placed on the concentrator and spun another time to achieve 98% salt removal, instead of two spins to achieve the same result with the traditional refill and re-spin procedure. When an appropriate centrifuge is unavailable, or for single sample processing, for gas pressure filtration, Vivaspin® 20 can be filled with up to 15ml and then pressurised for bench top concentration. For even faster processing, gas pressure filtration can be combined with centrifugation. 'Pressure-fugation' is particularly useful for difficult or viscous samples such as serum, when using a low process temperature, or generally when minimum process time is essential.