Vivaspin centrifugal concentrators are disposable ultrafiltration devices for the concentration of biological samples. Vivaspin 500 centrifugal filter units offer a simple, one step procedure for sample concentration with starting volumes up to 500 µl. They can effectively be used in fixed angle rotors accepting 2.2 ml centrifuge tubes. The patented vertical membrane design and thin channel filtration chamber (US 5,647,990), minimises membrane fouling and provides high speed concentrations. Vivaspin 500 units are available with PES membrane in wide range of molecular weight cut-offs. Concentrate recoveries of > 90% can be reached in less than 30 min. The dead stop pocket prevents concentration to dryness. High flux PES membrane 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 Volume graduation for easy reading/monitoring