Disclosed is an extracorporeal fluid flow system comprising : a connection passageway (112) for connection to a fluid source；a sampling passageway (113) for a fluid sample extracted from the fluid source, the sampling passageway (113) forming a junction (318) with the connection passageway (112)；an anti-clotting device (5100) operatively connected to provide one or more anti-clotting agents to the sampling passageway (113)； anda waste receptacle (325) adapted to receive the fluid sample having the one or more anti-clotting agents such that the sampling passageway (113) is cleansed prior to accepting the next fluid sample. Further disclosed is a method for maintaining clear passageways in an extracoporeal blood flow system and a method of assembling a fluid handling and analysis apparatus.
