The disclosure provides for a container system and method for the cryopreservation and resuspension of a body fluid. The container system may include a cryopreservation container comprising the body fluid in a cryopreservation liquid, a resuspension container comprising a resuspension solution, a connection tube sterilely connecting the cryopreservation container and the resuspension container, and at least one shut-off element actively associated with the connection tube.