Vivaspin concentrators are disposable ultrafiltration devices for the concentration of biological samples. Vivaspin 2 bridges the gap between the 500 µl and 4 ml centrifugal concentrators. They can effectively be used in swing bucket or fixed angle rotors accepting 15 ml centrifuge tubes. The patented vertical membrane design and thin channel filtration chamber (US 5,647,990) minimizes membrane fouling and provides high speed concentrations, even with particle-laden solutions. Vivaspin 2 combines the speed of the classic Vivaspin products with low internal surface and membrane area in order to achieve superior recoveries from very dilute solutions. Available with a choice of PES, Cellulose Triacetate or Hydrosart membranes, Vivaspin 2 offers the highest flexibility for process optimization. Another unique feature of Vivaspin 2 is the choice of directly pipetting the concentrate from the dead stop pocket built into the bottom of the concentrator, or alternatively reverse-spinning the concentrate into the recovery cap which can then be sealed for storage. Both methods result in near total concentrate recovery. Choice of three different membranes High retentate recovery > 90 % Vertical membrane desingn for ultra fast concentration Universal rotor compatibility Safe sample concentration due to dead-stop volume Convenient concentrate recovery by pipetting Optional re-spin for concentrate recovery Volume graduation for easy reading/monitoring