The present invention provides a surgical system 10 for aspiration of a biological material comprising a source of irrigation fluid 20, a collection cassette 30, a pump 40 for creating a vacuum in the collection cassette 30, a handpiece 50 applied to a surgical area for infusing irrigation fluid and for aspirating a biological material, conduits 60 and 62 connecting the handpiece to each of the source of irrigation fluid and the collection cassette and means 70 for isolating the pump from the handpiece to prevent creation of vacuum within the conduit 62 and the collection cassette 30 after receiving a stop signal.