A re-use prevention mechanism (160) for an apparatus (110) having a reusable part (120) and a single-use disposable part (130) connectable to the reusable part (120) is disclosed. The re-use prevention mechanism (160) comprises a blocking portion (1603) disposed, in use and between the disposable part (130) and the reusable part (120). An actuating member (1605) is operable between the blocking portion (1603) and one of the disposable part (130) and the reusable part (120) for moving the blocking portion (1603) into a blocking position upon disconnection of the disposable part (130) from the reusable part (120). hi the blocking position and the blocking portion (1603) engages an abutment surface (1206) ON one of the disposable part (130) and the reusable part (120) if a user attempts to reconnect the disposable part (130) to the reusable part (120) and thereby prevents re-connection of the disposable part (130) to the reusable part (120).